Conflict, discrimination, paranoia, kidnapping, slavery, and suicide
Trying not to assume that every individual is the theoretical perfectly rational agent, my world quickly goes awry.
Nothing interesting here, but I'm going to dodge the issue of the economy collapsing by asserting that the teleporter is based on previously known technologies used for extremely low-cost fabrication of arbitrary simple materials and machines (the next, next, next generation 3D printers).
If society was destined to collapse in the face of such easy duplication of objects then it would have done so already, built itself up again, and this time around the teleporter does not substantially interfere with the economy at that level.
The core innovation here is merely the ability to duplicate a fully-functional and conscious human being.
I'm going to assert that this technology isn't capable of scanning to storage for later playback. I'm assuming technology that works more like old analogue TV, where rather than trying to store the data before moving it on, it's managed as a continuous stream of extremely high bandwidth. More bandwidth than can feasibly be recorded and stored in a reasonable space.
The real reason for this is to keep some worms in their cans. There's already too much to discuss without the complications of backups, edits, and splices.
Also, if you have a storage medium that's capable of holding that much data, and it's smaller than the original object (otherwise just use the original object!), then what happens when you scan one of those storage devices? There has to be some kind of limit to the resolution.
If you need teleporter technology that can't be subverted for generating clones, you can replace it with wormhole technology or matter-stream technology. These change the placement within the universe of the original instance, so you don't have to worry about accidentally getting two copies (that one episode of ST:TNG not withstanding).
The use of a teleporter that involves producing a copy and destroying the original involves ... destroying the original. One assumes it's a painless death, but the copy is, in some sense, somebody else. I don't need to dig into it because it's been done to death already.
Likewise notions of identity and mortality in the face of a duplicate, etc.
The possible diversity of opinion is more important than correctness or logical consistency, so it's not clear that too much consideration helps in making predictions.
Assume that both options 1 and 2 exist, and they're used for different purposes or under different motivations.
- Teleportation should only be used if you can deal with the existential implications (that the original is killed). Looking around the internet, it seems that a lot of people think they can cope, so there's no reason to expect that to change. In any case, if the original realises its mistake during dematerialisation we'll never hear about it so it's immaterial (so to speak).
Not everyone will be happy to use a teleporter. The apparent normality of the teleportees as they become more common will lessen the anxiety of some. Social pressure and convenience will help too.
- Telecloning might be used practically for colonisation, and governments or corporations could drive these programmes promising both no interruption to your own life and an safe and exciting future for your clone (though conspiracy theories abound). Return trips for the clones may be forbidden because society hasn't got good answers for all the social and legal implications.
People may find their own philosophical objections to telecloning. Of those willing to go ahead, many will be averse to teleportation and take cloning as the safe alternative. Among them there may be some very callous attitudes to the fate of the clone. They might reason that a copy has no soul, or that the clone's consciousness is somehow more artificial than their own, or that so long as the original persists then the copy is simply somebody else's problem.
People should be wary of creating a clone too near to themselves. The scenarios have been played out in popular media for years, and the usual portrayal has messy outcomes. Whether those portrayals are realistic or not I expect that the perception would become more deeply entrenched as people refer to popular media to solve questions they've never had to think about before (because I'm pretty sure it's not mentioned in the bible). However, so long as it's possible some people will try it.
The clone knows it's a clone, and it knows that the original who chose to create it had a plan and presumed some authority over the copy. But that knowledge that it's a copy is only theoretical. In terms of real motives, the subjectivity of its situation quickly changes its attitude (as per the C&H cartoon in another answer).
Serious conflict is inevitable here, and could plausibly lead to violent crime. It may seem exceptionally difficult for someone to kill their duplicate, but an alternative view, that the other is superfluous so long as one survives, may take over.
Triggers could be anything from stolen funds (is it even stealing?) to "stay away from my wife!". This is where things might start to turn ugly.
Because it's easy from a naive perspective to take the intentions prior to telecloning as concrete, and because the original stayed home while the clone went away and would be the usurper should it return home to cause any kind of trouble, society will likely side with the originals.
Laws may be passed discriminating against clones (but not teleportees, who are technically the same but have no such conflict and are too numerous to ignore).
It doesn't have to be all clones that cause trouble. Just enough to get in the media; and policy doesn't have to reflect a majority view, it oftentimes simply reflects a shoutey view. Even if it's not law it may be popular perception.
If there are bad guys out there then they have to be identifiable, and a perfect duplicate of a good guy is the least identifiable thing in the world (except to the original).
Since the key identifier of a clone is its travel history, tracking this closely is the obvious solution. Teleport and teleclone machines may be modified to mark the copies they produce. Perhaps to pepper them with a benign chemical marker to make them distinct from the original. Something with an embedded serial number, so every transit or copy comes out unique.
But public perception and policy are inevitably so simplistic. What about the tricky cases?
Kidnapping and slavery
What about teleporter fraud, resulting in an illegitimate original persisting at the same time as the teleportee? The operator may deliberately keep the original to sell as a slave or to hold to ransom. The law says the teleportee has restricted rights, but it doesn't realise this at first. This person didn't even have a plan for a copy that they can be expected to follow through with, so there can be no obligation on the copy to get out of the way. At least not morally, but the law might say otherwise.
These poor souls (or "un-souls", or whatever) will be poster children for a fight they never expected to be involved in. The fight for equal rights for clones.
Similarly there are the clones who went off on government/corporate contracts. Their working or living conditions might be far more terrible than they were led to believe, and they want out. If some escape and are able to make their way home they're going to end up in the same situation. The original has all the rights and the clone is merely the victim of misrepresentation and/or its own [pre-copy] callousness.
Can a clone even travel home? Its original may have been one of those people too afraid of teleportation to use it, consequently the copy itself has the same fear. Teleporting means certain death, and what benefit would it gain from sending a copy of itself back home? At best it could try for some kind of revenge or to tell people what's really happening; but in a paranoid surveillance society it may not get very far, and may soon realise it's best keeping its head down or shouting about conspiracies like a crazy person on the street.
Or consider the opposite. Imagine somebody too fearful to go through with destruction implied by teleportation, but so driven to live a new experience on a new world they try telecloning. What, then, if they realise their old-world life is awful? They become jealous of the fate of the clone.
The idea that there is a second self out there to keep continuity, coupled with depression, may make it easy to elect to perform a post-hoc teleportation.
Along with misrepresenting a teleclone as a teleporter, there may be another way of fabricating discreet copies of teleportees. Skim off the communications between two teleporters, being careful to not interrupt the signal, or to replay it onward to the destination if necessary, and run that into your teleclone receiver. This copy can be enslaved or interrogated without anybody knowing.
Alternatively, and this may apply to some strict teleporter technologies as well, you do interrupt the communication so the traveller never arrives at their destination and then hold them for ransom.
Memories are more fluid than most people like to admit.
A clone might actually forget that it's a copy. This could happen because it changes its memory of the teleclone to be a teleport, or it could go so far as to forget the whole process and just have a discontinuity or fantasy explaining how it got to where it is. Such a change might be a necessity to reconcile the feeling of continuity with its pre-clone life. If it feels continuous then perhaps the notion of being recently fabricated with a complete set of false memories just makes too little sense to retain as a memory, and so it's unconsciously dismissed and replaced with somethin more plausible.
People who make clones close enough to come back home discover that they can't get along with themselves, culminating in some instances of violence and/or murder. This hits the media, then moral panic, clones lose freedom and rights, surveillance grows stronger to track clones. Complicated cases and misadventure eventually help to challenge people's prejudices. Then I taper off because I can't seem to imagine happy things.