The new rioters weapon of choice

The nation of Futurestan is a typical overly complex futuristic dystopian utopic society of the 23rd century. Fossil fuels are widely unavailable because only barbarians would think it was a good idea to destroy a non-renewable resource in a non-renewable way. This is great news for the environment and global warming advocates, but not so much for big petroleum, though this is 200 years in the future and everyone to too busy with their BTL (better than life) simulations to care about Exxon-Valdez or whatever.

However, it isn't like the public could learn about Exxon-Valdez anyway because 200 years of government censorship has caused large portions of human history to not be there no more. Yes Futurestan has decided that it is is the best interests of society that they don't know about fossil fuels, Enron venture capitalism, or the works of Ayn Rand among other things, so they just erased all of it via the magic of I said so.

PROBLEM IS that the more logical ones who weren't expunged during the great culling are causing problems. Protests in the streets. But since all police are independent contractors, the first amendment applies even less than usual and protest has become synonymous with riot. Protrioter #4 reaches for xer molotov cocktail to throw at the police only to realize xe doesn't know what gasoline is and is pretty sure that cops have figured out how to be fire proof by now.

YOUR TASK: Figure out what protrioter #4's protriot weapon of choice is. Chances are in 200 years police may or may not have figured out how to deal with flammable liquid + flaming rag, via tanks, robots, or space age breathable fabrics. However, it has to be cheap, widely available, damaging, and fear inducing. Basically: what is the molotov cocktail of the 23rd century?

• I fail to see what part of this is off topic, it is not about idea generation though a certain speculation about what weapon could be used in the future without the use of liquid flammables and fossil fuels. – Magic-Mouse Jun 9 '15 at 11:18
• The short answer is, whatever the technology of the time provides cheaply and easily. Molotov cocktails are common because current technology puts glass bottles and petrol within easy reach. Future technology may provide force field manipulators that can be turned into weapons, for instance. – Paul Johnson Jun 9 '15 at 20:24
• There may not be a fossil fule industry that could keep millions of cars running all day, but for a molotov you don't need a lot of fuel. People should be able to brew a liter or two of hydrocarbons at home, from booze, which they will probably brew at home anyway :-), or from algae or whatever biomass they can get hold of. – JimmyB Jun 10 '15 at 13:09
• If you have control of the media, why have a public confrontation with the cops at all? Damage things where the cops are not. – Oldcat Jun 10 '15 at 23:28
• ... Is it just me, or does alcohol burn just fine? – kutschkem Jun 11 '15 at 8:53

I'm going to go with malware.

Granted, this is based on current trends that may or may not continue all the way to the 23rd century, but you did mention most people being busy with better-than-life simulations. Since malware is highly likely to be able to affect these somehow, especially on those fringes where "build it fast" and "build it right" conflict - which, not coincidentally, are likely also to be those places where protriots are most likely to occur - getting all the virtual lights to flash your message is an integral part of the protrioter arsenal. Especially if those virtual lights are in the headsets of the cops' HUDs.

Also, if voice recognition software and/or programming languages advance far enough in those two hundred years, you might very well have custom code being created mid-protriot. Gives an entirely new meaning to the term "flamewar".

I realize you may want something a little more physical, but it's not entirely clear what protrioters will have on hand to work with/repurpose. Two hundred years is a long time, after all - alcohol might still be the flammable liquid of choice, or they might have figured out how to synthesize and distribute, say, nitroglycerin.

• and if there's wide spread automation, malware in say your Google driving program would be extremely fear inducing. +1, I like it. – Jim2B Jun 9 '15 at 3:26
• Related: David Langford's basilisk stories. Stories include BLIT, comp.basilisk FAQ, and Different Kinds of Darkness. Though as noted in DKoD, this technology would be found on both sides of the riot. – user487 Jun 9 '15 at 13:43
• That probably means that the rioters don't riot, but sitting at home and causing massive economical damage by manipulating a lot of people, maybe inducing a mass panic. That might even easier than attack the HUD of the police that might be better secured than most peoples BTL. – Mnementh Jun 9 '15 at 14:08
• If the police are using HUDs, your malware could fool them into thinking that there was a real physical riot when the rioters were in-fact at home introducing more malware. Very interesting. Expect all law enforcement agencies to be "hardened" against anything the rioters would think to do. But if there were sympathizers in the law enforcement ranks, that'd make the introduction of the malware wwaaayyy easier. – Jim2B Jun 9 '15 at 16:06
• @MichaelT Interesting idea, basilisks. Will have a look. – Stephen Voris Jun 9 '15 at 23:12

While not as impressive, Molotov cocktails made with 100% alcohol would be rather nasty. And, of course, they are entirely Green.

EDIT - Actually, I think I missed a trick. Since this is The Future, after all, we can assume a few technological tricks are available. In this case, 3D printers allow making glass vessels of arbitrary design and cheap production. Also, cryogenic super-coolers are widely available and cheap.

With these two assumptions, you can do really interesting things with an alcohol-based Molotov cocktail. Specifically, you can make a 2-part bottle. Half of the bottle is a normal container - the other half is a thermos flask. Alcohol goes in the normal part, and you use the super-cooler to produce liquid oxygen to fill the thermos section.

When this sucker hits something and breaks, the results should be pretty spectacular. See https://www.youtube.com/watch?v=UjPxDOEdsX8 for a demonstration of how to get a charcoal grill up to heat in 15 seconds.

Of course, you need a pretty sophisticated pressure relief valve on the LOX section, but that's what the Hypernet and 3D printers are for.

END EDIT

Thermite

Grind up Aluminum and rust into a fine powder. Combine in roughly equal portions. Ignite with a high temperature fuse (like burning magnesium).

Burning Thermite

Burning Magnesium

It will generate a great deal of heat and melt or burn its way through most other materials including steel (the amount it'll melt through depends upon the amount of thermite used). It will ignite nearby combustibles. Perhaps not as fear inspiring as a Molotov cocktail, if used properly it could be highly effective.

You could combine this with some other substances (e.g. Titanium and its alloys) to induce fires that are extremely difficult to stop (requiring something like vacuum, dry $N_2$, Class D extinguishers, etc.).

Burning Titanium

Using water or CO2 fire suppression systems just accelerates the Titanium fire. You can do a variety of interesting things to this combination (e.g. grind the Titanium into coarse particles and disperse in an explosion) to make it "more interesting".

As a powder or in the form of metal shavings, titanium metal poses a significant fire hazard and, when heated in air, an explosion hazard.[89] Water and carbon dioxide–based methods to extinguish fires are ineffective on burning titanium; Class D dry powder fire fighting agents must be used instead.[5]

• I don't think that's weaponizable by rioters. Thermite is hard to ignite: you need something like a fuse of magnesium ribbon. Thermite is a powder: how are you going to deliver it? You need a container that's strong enough to keep the components together while they burn. Thermite just gets hot: as soon as you try to scatter the products, the reaction stops. You can't get a spray of molten iron or anything like that. Yes, the military have thermite grenades but they're not pure thermite and they're used in cases where "just getting really hot" is enough, i.e., anti-materiel, not anti-personnel. – David Richerby Jun 9 '15 at 8:59
• Thermite scares the crap out of me...use it on a bridge...yeah. @DavidRicherby keep in mind that maybe these things are easier to get in the 23rd century. – James Jun 9 '15 at 18:41
• Put the thermite in a titanium casing - nasty. – Jim2B Jun 9 '15 at 19:16

I see that fire is a common trend in the answers here, and while I do agree that in general fighting everything with fire is a good solution; I must dissent:

EMP

As per your cost requirement I honestly don't know how much it would cost to make EMPotov cocktails (presumably electronics and the like would be rather cheap). The general idea here is that by the 23rd century our climb in technology will likely have continued unabated. Smaller and better computers will have made their way into every aspect of our lives (where they aren't already present in this modern age). Computerized (possibly electric/laser) guns, HUD elements to glasses, visors, and police helmets. Arm mounted tablet like devices for communicating with HQ, etc.

The above also doesn't include internal devices; It's quite likely we'll have some fairly elaborate implants that would control/display a number of common processes or tasks. Perhaps the "BTL" simulators you mentioned required a synaptic jack (think The Matrix) in order to get the "better-than" part to work out properly. Having something connected to the nervous system short out would be rather problematic.

EMP devices cripple a future society by attacking the underlying foundation that everyone has become accustomed and reliant upon, and soon the "Protriot" with the hockey stick or baseball bat is looking pretty well armed.

• An actual electronics-damaging EMP burst requires either a huge release of energy or directly connecting the circuits you want to damage to a still-big electrical source. Lightning is technically a form of natural EMP; even though it carries a huge amount of energy, it's still only a problem for electronics connected directly to or within feet of the path it follows. Due to inverse square law, to get an EMP that actually damages a lot of electronics in an area, you would need nuke levels of energy release. Local jamming of wireless signals would be the limit of the capabilities of a rioter. – Joshua Hanley Apr 18 '19 at 14:48

Not as cheap as molotov cocktails (and that's a huge advantage of them) but lithium ion batteries burn pretty well. They are also hard to put out, and you can't put out the fire with water.

Probably pair it up with a circuit that intentionally overloads them quickly and you can do a ton of damage.

I suggest a simple mix of pure alcohol and agar-agar (E406), you know, the powder you use to make a vegan jelly. The alcohol will burn and, mixed with agar-agar, you will have a flammable jelly, natural, 100% vegan, gluten free and renewable.

The mix is needed so you don't have just a puddle of fire but something which will stay on your target, cop or tank.

Sling and stone. It's a long range weapon with infinite ammunition. It's cheap, deadly, and highly accurate with training. It also makes it past metal detectors and chemical sniffing dogs, plus anyone could make one at home. Additionally, in keeping with your question, fire-retardant materials are ineffective against it.

• Welcome to the site Truth. I am not sure your answer really fits the bill, take a read of this part However, it has to be cheap, widely available, damaging, and fear inducing. Basically: what is the molotov cocktail of the 23rd century? I think the sling definitely misses on the fear inducing (as far as weapons go) piece and potentially on damaging depending on the armor the police wear. – James Jun 9 '15 at 18:16
• @James: Anyone who wouldn't fear a sling doesn't know what it can do. In a trained user's hands, they're as deadly a weapon as anything invented before the advent of gunpowder, and because they deliver their impact as a blunt impact and not a penetrating edge, they're highly effective against armored targets. As one author wrote regarding the tale of David and Goliath, it's no surprise at all that David won, since "[Goliath] had about as much chance of winning that fight as that poor fool who pulled a sword on Indiana Jones, and for the same basic reason." – Mason Wheeler Jun 9 '15 at 20:27
• @MasonWheeler also "anything invented before the advent of gunpowder" is still a lot of very deadly things. – kutschkem Jun 11 '15 at 9:04

Whatever replaced fossil fuels

Fossil fuels are currently used so often because they pack a high energy density per unit volume, which makes them convenient for powering things like cars and weedeaters.

Although fossil fuels don't have the highest energy density obtainable with modern technology, they also can't be used to make nuclear weapons, which is nice, I guess.

Worldwide energy demand and consumption has increased rapidly and shows no signs of stopping.

Assuming your setting isn't some kind of agrarian dystopia/utopia, energy consumption will likely be at least as high as it is today, even if the form-factor has changed. People are going to want use some kind of energy-dense container to carry and consume energy.

Unless peak oil was the reason fossil fuels are no longer in use, the most likely reason they aren't still around is development of something cheaper or denser, energy-wise.

What that looks like is up to your imagination and the technology level of your world, but, whether energy is packaged in some kind of super-advanced batteries, hihydrogen fuel cells, thorium microreactors, or matter-antimatter annihilation in tiny personal extradimensional pocket universes, there is usually a way to compromise the storage and release the bulk of that energy very quickly.

For example, the high-tech energy container of today, Li-Ion batteries, can be overcharged, heated, or breached to cause an explosion. And they have a relatively low energy density; whatever replaced fossil fuels could be a lot more exciting.

So people will use that.

Or they'll make ethanol in basement stills and use that in Molotov cocktails. Sometimes the old ways are the best ways.

• Exactly. They will have potent power sources and those can always be abused and/or cause accidents. Maybe their vehicles are powered by nuclear reactors (ouch!), or there is a power grid of high-energy plasma available everywhere that can be sabotaged, or ... – JimmyB Jun 10 '15 at 13:51

Network Jamming

The cops are linked up, networked and in contact with databases to help them deal with the protesters.

As such cheap throwaway Cell Phone Jammers on steroids are going to be very useful. The cops are being too coordinated? A dozen people drop their backpacks and the airwaves are filled with noise drowning out every cell signal and police network signal.

HERF Gun

Possible to build for a few dollars, ideal for burning out those cameras and smart crowd control devices the police are pointing at you from a distance.

Take dry milk powder, disperse it into a huge cloud of fine particles. Then it's pretty easy to light a match and make an explosion. Dry milk powder is extremely flammable.

Also, very fine sawdust particles do the same thing.

Neither requires petroleum.

And milk and wood are probably readily available and inexpensive.

• True, but getting the exact concentration an uniformity of milk powder or saw dust to air to make this explosive is very very difficult. – Jim2B Jun 9 '15 at 16:02
• Grain dust works as well. – James Jun 9 '15 at 18:41
• @Jim2B Accidental ignition requires proper concentration, with intent you can cheat by preheating the dust above its ignition temperature in an air tight container. (Remember a safety valve to let pressure out.) Of course, making the proper container (secure but ruptures when you want it to) is probably just as difficult. – Ville Niemi Jun 10 '15 at 16:45

Normally this is made with something like glycerin and gasoline. The glycerin is what allows it to stick to things while the gasoline does most of the burning (glycerin also burns).

As above, you may replace the gasoline with other easily ignitable liquid (say high proof alcohol) and use it for the same purposes.

Water. In 200 years, the means by which we obtain our hydration will likely be encapsulated. Tech will no longer require the shielding from moisture and for a cost savings, big corporations would have removed those protections from all the newer devices. Mind you some of the older (see accessible to the masses) devices would be archaic enough to be waterproof. Chucking collected water at the police force could effectively disable all offensive and defensive capabilities as well as communications. This could be especially problematic if they are emotionally reliant on their connection to an avatar.

The 'better than life' simulations are made possible by implants that everyone is given at birth. These also serve as a means for those in power to keep the population subservient and docile, rewarding them with pleasure and interrupting their natural vision to give them something akin to rose colored glasses that changes their view of the world and gives them that rosy outlook. The implants malfunction in some people which allows them to learn the truth and become disgruntled. They spread this truth by inventing devices to disrupt the implants temporarily in others. It is these devices and devices like it that are the actual weapons. They disrupt communications signals. Cell phone/radar jammers.

The police force is now remotely controlled robots with limited AI to enable them to be somewhat autonomous. Protesting in the streets really isn't going to get anyone's attention because the implants will twist it into a celebration and nobody would physically leave their better than life simulations to join in the celebration because it's 'better' to join in via cyber link. So an actual futuristic protest would require them to hack into the server so as to get the word out en mass. Nobody talks face to face anymore.

Throughout the day people get exercise generating electricity, so they are all healthy and fit for the most part. But government corruption still exists and people are allowed to eat rotten food which makes them sick, but they don't realize it because of the implants that simply makes whatever they eat taste delicious. So some people die. The government doesn't care so long as they remain in power. And turning potatoes into electricity through the populous gives them power that other people don't have. So those who manage to see things the way they are really do have something to complain about.

They don't protest in the streets though, although a showdown against the robotic remote controlled police might take place in the streets. Basically, nobody goes anywhere since their food can be liquified and delivered via pipeline and anything else they need can be delivered by robotic couriers. Those that escape the illusion find that they are living in cockroach infested hot or cold cramped apartments and when they actually look outside, instead of seeing lush green lawn, they see a narrow passageway with robot couriers going about their routes. Some couriers are carrying corpses with cockroaches still eating out the eyes. Some are carrying children who are ready to take the place of the corpses in their apartment where they will produce electricity to more than power the illusions they are given.

So the weapon of the protester is related to the tech that enslaves everyone. It is a simple bit of electronics with a large enough power supply to block signals long enough that they can dismantle and/or rewire the robotic police force. One thing they have on their side is that the uncaring government hasn't bothered to upgrade old equipment, so some of it is not very reliable and allows them to escape many close calls. Guns which the police bots have installed misfire due to neglect. Old security cameras have long since been sabotaged and replaced with a repeating loop of generic footage so that corrupt security at one time were able to steal.

Not everyone joins the rebellion. Many treat the interruption of their illusion with contempt. 'How dare you interrupt my pleasure with this? Ugh! Let me go back immediately!' They blame the messenger. The first interruption devices are crudely built out of old appliances that simply were never disposed of, and some are overpowered resulting in the destructing of the sensitive electronics in the implants when activated too close. This results in a number of people who don't want to be awake trying to get to the government to have their implants repaired. Unfortunately, as they are not in their hovels, they are considered rogue and dealt with ruthlessly. They are unable to communicate well without their implants. They mumble because without functional implants they don't have the automatic inflection correction, which is similar to auto spell correct anyway.

The leaders are smart and cynical electronics engineers. They are able to reverse engineer most tech in a short time, mostly because the tech used on the robots is modular and meant to be re-used or repurposed. The problem is in reprogramming it. They need to find or build an interface like a laptop or a phone, none of which are in use anymore since all communication was done through the implants, which are themselves too small to rework. Through sheer luck they are able to find an old Raspberry Pi 5 and they boot it to find it is running GNU Hurd.

Although recruiting police to their cause is an initial strategy, they find that using the government's own reality manipulation A.I. works better at shutting them down as they are fooled into thinking all insurgents have been caught or put asunder.

The final (maybe) showdown reveals the city to be run by a fat cigar smoking red meat eating fossil fuel burning elitist who has opted to experience carnal pleasure without any implants of his own. He and the other elitists of the world number about 1000 altogether and he calls his brethren for help. They decide the easiest thing to do would be to detonate a neutron bomb so that they will clearly have the upper hand with their fossil fuel burning tanks against these nearly naked citizens who have very muscular bodies from creating electricity most of the day for most of their lives. What weaponry they have is all electronics based and susceptible to the neutron bomb. As the rebellion seems to be crushed, suddenly the elites realize that there are a trillion new protestors to deal with as the neutron bomb has awaken the masses! Their electricity production ceases and their own opulent lifestyle has not left them with much fossil fuel to combat the masses. Who will win?

• Wow... way to take the question and run with it. Lots and lots of great plot hooks in here. – evankh Jun 10 '15 at 3:37

I think IED's (improvised explosive devices) will still be with us in the distant future. Simple homemade explosives can vary considerably, but the materials are often cheap and fairly accessible.

All you really need is a vessel, shrapnel, and a compound that will rapidly produce gasses when mixed or ignited.

Molotov cocktails are easier, but they're not nearly as effective or as scary as pipe bombs.

nitrate based explosives.

The only reason rioters use molotov cocktails today is partly because its trivially easy to make a firebomb (gas + rag + bottle, so simple) but also that making explosives is significantly more frowned upon by the authorities. In the dystopian future, I feel such niceties would be ignored.

As such, making home-made explosive devices, perhaps with shrapnel, would be more of a weapon of choice. Fuses can be interesting, but either radio detonators, or more simply a small bomb with a fuse attached to a long bit of string (that pulls the pin when the bomb has travelled to the extent of the string, raining nails down on the security forces from above their heads) would do.

Simple nitrate explosives are pretty easy to make even if they don't pack as much bang as professionally made ones, and nitrates are widely available (assuming they still eat vegetables in the far future).

Joining the ranks of the EMP crowd I'd go with Explosively pumped Flux compression bombs. These work by generating and compressing a magnetic field using a power supply, a coil and some explosives. See the the wikipedia entry for a full description and description of how they work.

The magic trick with most of these emp type weapons is the power supply but given we are talking 200 years into the future it is not unreasonable to assume that power storage (batteries) have got a lot better. Look how far we have come in the last 100 years and extrapolate forward.

An explosively pumped flux generator is actually quite simple to build given a power supply and explosives. However it is single shot, quite small, and usable like a Molotov. The hardest bit to get hold of is probably the explosives to blow the coil.

These would be used in a riot to disable the police vehicles and any electronic equipment on them. Cameras, Radios, movement assist devices. This might even completely immobilise them depending on how their armour works.

It is far in the future... there is no fossil fuel. Cars/Trucks/Etc still need power/energy, perhaps in the future they invented some sort of plasma fuel cell that gets popped in and out of their car. Because it is the future, these fuel cells are normally 100% safe... but... by carefully removing the insulation and blast proof casings a copper wire can be run from the pos to the neg... eventually the cell explodes spraying the area with super heated plasma.

An old trick from the Anarchy Cookbook, courtesy of the Jolly Roger...tennis ball bomb. Cut a small hole in a tennis ball, fill very carefully with snapped off wooden match heads, toss and enjoy. I never tried it because I was afraid I might hurt someone/thing unintentionally, and I of course DO NOT recommend trying such in real life, but I think it's plausible. Maybe stick a small piece of coarse sand paper or something inside to ensure there's enough friction for ignition. And a few tacks or small ball bearings would bring a real feel of terror and pain to it, it would certainly hurt even if it weren't lethal.

• Well, that fits the 'widely available', 'damaging', and 'fear-inducing' properties, certainly... I'm less certain about the 'cheap' part, though - anything one has to do 'very carefully' probably isn't going to be done in the middle of a protriot. Of course, the same could be said for my answer. The cost-to-impact ratio is a bit different, but still... – Stephen Voris Jun 9 '15 at 23:00
• you start buying 50 zillion wood matches in Futuristan, you soon get the police at your door. – Oldcat Jun 10 '15 at 23:30
• Haha those are both good points. It wouldn't be something you could probably make ahead of time and carry around with you, Stephen and I hadn't thought of that. As far as the 50 zillion wooden matches...yeah I can see how that might raise a few alarms. What types of items might the government not try to crack down on, or might draw less attention when buying/acquiring in quantity? – Dawn Deschain Jun 12 '15 at 22:27

Malware for the brain via the eyes

In the world of David Langford's basilisk, malware for the brain was found that could come in through the eyes. This is akin to Snowcrash which many are familiar with but it works on all people (not just the coders).

All you need to do is present the image and depending on its lethality anything from instant death to seizures can be the result.

The idea behind this was that the state of the brain is determistic and if you can cause it to think unthinkable thoughts, it will crash (for varying degrees of crashing - sometimes its a reboot, other times its "bricked" in modern parlance).

This can lead to worlds where just looking at a spraypanted stencil on the side of a building can kill you. Put it on a placard that you are protesting with and the other side falls down (one should avoid using the ones that kill and instead go for the seizure inducing ones). One could also look at targeted forms where a one traces out / etches on the visor of the image that must not be seen with a laser. Blindfolded protestors, arms linked, with tshirts showing dangerous images. Lots of ways to present visual information to someone.

Some existing accessiable stories by Langford:

In particular from Different Kinds of Darkness:

“Yes. Mistakes do happen.” Her face softened a little. “And I’m getting carried away, because we do actually use that BLIT image as part of a little talk I have with older children when they’re about to leave school. They’re exposed to it for just two seconds, with proper medical super­vision. Its nickname is the Trembler, and some countries use big posters of it for riot control—but not Britain or America, naturally. Of course you couldn’t have known that Harry Steen is a borderline epileptic or that the Trembler would give him a fit . . .”

And a reference from the Accelerando universe by Stross:

Not everything is sweetness and light in the era of mature nanotechnology. Widespread intelligence amplification doesn't lead to widespread rational behavior. New religions and mystery cults explode across the planet; much of the Net is unusable, flattened by successive semiotic jihads. India and Pakistan have held their long-awaited nuclear war: external intervention by US and EU nanosats prevented most of the IRBMs from getting through, but the subsequent spate of network raids and Basilisk attacks cause havoc. Luckily, infowar turns out to be more survivable than nuclear war – especially once it is discovered that a simple anti-aliasing filter stops nine out of ten neural-wetware-crashing Langford fractals from causing anything worse than a mild headache.

In my first answer I got carried away with inspiration and did not pay due attention to the OP's scenario. I will try to make up for that here. The protrioter is reaching for something: cheap, widely available, damaging, and fear inducing.

This could be:

• microwave oven
• lubricant, paintball, graphite
• communications jamming device
• pipe bomb
• laser
• sling or slingshot
• steel pipe
• yo-yo, bolo whip, bolas, boleadoras

Although fossil fuels will no longer be used there will still be cars--hydrogen fuel cell or all electric plug-ins using lithium batteries or even something futuristic with a higher energy density or maybe something cheaper such as a sodium battery. (Currently sodium batteries are used on trains; they have an operating temperature range of 300 to 350 degrees C). Protrioters, having played warfare video games, will be familiar with various tactics. Wireless remotes for detonating a hydrogen fuel cell or a lithium battery from afar will be available, although not reliable with various communications jammers in use. Another detonation method is optical signaling. The detonator would be triggered when it receives the right signal from a certain spectrum laser. So IED's may be rigged quickly from a couple of cars then the protrioters tactically retreat allowing the 'crowd control' to advance until 'boom'. The protrioter in the scenario could be reaching for the laser device to trigger the IED.

A technologically advanced protrioter might have a 'selfie copter' on hand to use for advanced information gathering or dropping stuff from the sky. The little quad copter can even be mounted with a laser used to blind or annoy the crowd control. The auto-darkening lenses in the face shields would go to black, blinding them temporarily.

Even without petroleum there will be a need for lubricants so there will be synthetic lubes some of which are flammable but maybe the point is to disrupt rather than burn. Making a road slippery can hinder heavily armored walkers more than the lighter weight opponents. A packet of graphite delivered just so could obscure vision. So the protrioter might be reaching for a paintball or a similar ball of graphite or silicon based lubricant.

Simple things like a length of steel pipe as a melee weapon might actually be more common and somebody will need to chip up the sidewalk with one to provide more ammo for the slings unless there is a gravel parking lot nearby. A weight on the end of a rope or chain (yo-yo) is an ancient weapon which is easy to improvise. It depends somewhat on how much planning has been put into this conflict or how spurious it is. If this is a case of peaceful protesters suddenly having to MacGyver a defense then it will be limited to what they have on hand. If it is a case of protrioters that know to expect conflict, but guns and gunpowder are not available, then we can expect more complex devices that take time to machine or 3D print. I think fleets of remote controlled quad copters will be used to rain stones or sharp objects from above. The pilots don't even need to be in the streets, but merely supporting the protest from the safety of their living room or nearby in a smart car. It would even be possible that AI makes these quad copters somewhat autonomous and can be told what to do with simple verbal commands. Fetch rock, deploy at 350 feet at such and such coordinates. Repeat.

Protrioters, trained from video games, will use tactics like taking up a sniper position in an upper floor of a nearby building. They can use the building's power to power a rail gun. They could, with enough planning, make a rail gun from a bunch of microwave oven transformers. (In the real future, governments will read this and start planning buildings to supply high voltage directly so that the use of transformers in appliances is phased out. There goes the ability to easily build rail guns!) Still, microwave ovens can be used to rain down microwave energy heating the streets and melting the slip resistant soles of the boots into slippery flat soles. Anything metal will get hot quickly. And of course the water inside the eyeballs of anyone in the way may expand causing blindness. For me, the concept of the use of microwaves as a weapon is the most fear inducing because you cannot see where it's coming from... you can't see it shooting down on the street in front of you... you just walk into it. Probably your first indication will be the guy in front of you convulsing from his brain baking and by that time you're half baked yourself. Popular media shows gerbils explode in the microwave and this notion can be tapped to inspire fear but in reality aside popcorn and beans, not much actually explodes in a microwave. It's more like being exposed to any other kind of radiation... you get burned; you sizzle.

As for something on hand that a person throws, this is more likely to be a set of bolas. These can be improvised from wire and lug nuts. A bola can be used to tangle the feet of a crowd control mech, possible causing it to trip and fall face down. This is not as damaging or fear inducing as a pipe bomb, but I think they are more likely to be in the arsenal of peace loving protesters.