In the near future, screens and technology will be implanted in us so we do not need to have another physical device. When a person is in prison, they are not allowed to have access to technology and other resources without permission. How would this be handled if the technology was implanted? Would it be ethical to forcefully remove the device on the start of the prison sentence? What about in jail before the person is convicted of a crime?
Either remove the tech in question, or even better, lock it down, and use it to further monitor and control the inmates.
That tech can be used to educate / brainwash inmates by constantly broadcasting educational programs, or offering them some entertainment as a reward for good behavior.
Furthermore, you can probably tap into what they're looking at at any given time, and even "blind" them if they're actively involved in a fight, or mischief.
Here's the deal with crime and punishment.
Generally speaking while prisoners in some countries retain SOME rights they lose rights in every country while incarcerated and sometimes, depending on the severity of their actions lose rights even after serving their time.
Ethics is a matter of social norms. Not right and wrong.
You can claim that ethics is based on good versus evil or religion and therefore ethics is innate and immutable but that is simply not true.
Take the Catholic church as an example. It silently consented to the trans Atlantic Slave trade. Burned scientists and witches alike...and a whole host of other sins aside. As society changes, rules change.
So. That in mind. Your society dictates what is ethically acceptable within said society.
The only mostly universally agreed upon human rights are the basics (the UN bill of human rights is delusionally optimistic and VERY western/progressive, and as such wouldn't use it as a baseline).
That being: Food, Shelter, Water ...but that's about all we can usually agree upon as human beings.
Taking a cell phone out of your arm doesn't really violate any basic human rights.
If your society agrees that it is not a violation of rights for a prisoner to lose these privileges then you're good to go.
There must be some way to get into the system, install a new version of the firmware (now with 20% fewer bugs!!!), reboot it after a crash, etc.
After the first cases have wormed their way through a series of administrative orders, court injunctions, decisions, and appeals, there will be rules that inmates must surrender the access codes to their systems. What can or cannot be done depends on the political climate at the time, perhaps data cannot be used but the system can be shut down, perhaps there will be a full download for analysis by police AIs, perhaps the system will go into some sort of "airplane mode" with stand-alone use only.
Remember Medical Implants
It is quite possible that implants for medical purposes will be common before "elective" implants reach the market. Pacemakers. Hearing aids. Artificial eyes. Prostetic limbs. Taking that away from an inmate, especially one who is awaiting trial and not yet found guilty, might be a civil (or human) rights violation.
Note that in some places in the world, inmates have a right to free and adequate medical care. That might even include new implants if the old ones wear out.
If the legal precedents are set with medical implants in mind, your story could get interesting ...
So it kinda depends on what the implants do.
If you watch anything about prisons, you'll see what a bored person with a lot of time can do with very minimal resources. Making a weapon out of a toothbrush, or a bit of stone, or compressed paper... So leaving even deactivated hardware is just asking for trouble, because all you need is someone that figures out how to reactivate it, and you'll have inmates getting up to mischief.
Even if they have to carve into themselves to turn it on.
But there is also a case for allowing limited technology use. Some prisons have been rewarding prisoners with tablets for good behavior.
Some implants might have a health reason, such that removing or disabling them might cause the prisoner to die, so that should be taken into consideration.
Now stepping a little closer to the ethical line, if you have bio implants there might be a way to use implants to the benefit of the prison.
Maybe implant something that shuts off nerve impulses down the spine and temporarily cripple people at will.
So you have a prison riot start, the warden just flips a switch and all the prisoners fall down. The ones that need medical attention get taken to the infirmary, the rest get dragged to their cells, and then when everything is secure you turn them back on.
Take it one step further, and you can put a trouble maker into solitary right in their own head. Enter a command and their hearing, sight, and maybe other senses just stop working.
Another step over the line and you make all signals register as pain...
One easy answer would be a futuristic version of "MAC address filtering" where the unique ID of wifi cards are filtered to allow access to a wireless network or deny it (less often used).
In the scenario you describe, the hapless prisoner wouldn't have his tech removed as much as disconnected or - based on Bellerophon's comment to your question - un-powered/switched off.
This is where you run into an odd confluence of convenience, security, and ethics.
One of the things you have to do to control the prison population is to control communication with the outside world, but it would be unethical to totally remove the ability in a permanent way. Implants would be a grey area, because that would impede communication, similar to cutting out a prisoners tongue. On the other hand, you can always replace the implants.
Any number of blocking, jamming, or other techniques might be used for short term incarceration like between arrest and trial. The protocols would have to be different for those incarcerated for long periods of time.
Perhaps the minimum security prisoners will just have the implants bricked temporarily by firmware update, since sentences are shorter, and the surgical removal would probably be expensive.
When the convicted prisoner reaches their long term destination, The most secure thing might be to actually remove the prisoners implants, replacing any which are health related with secure, prison versions. almost any technology is going to be hackable, and we have learned that, given time, the bad guys will find ways to circumvent anything software related. Imagine what would happen if a prisoner uses his own implants to start messing with the guards implants, like a phone call signal to distract the guard just long enough to get something sharp in between somebody else's ribs.
Also keep in mind that humans are clever monkeys and will not only circumvent your security, but will find creative and unpleasant ways to use it against you. You would be amazed at the 'harmless' objects that can get turned into shanks in a prison.
Just Fry It
Use a targeted EMP that will destroy the tech.
I'd imagine the cost of such tech is pretty low, so if they're a certain level of criminal, you just copy the data from it, fry it, and then reimplant something after they're released.
Block the Wireless
There are so many different technologies to inhibit wireless transmission that for low-level criminals who'll be released quickly or pre-convicted/sentenced criminals you can just create a wireless hole. This could also be targetted into only specific areas that guards aren't always inhibited, but prisoners always are.
Similar to Jym's answer, I'd use a pharadehic cage around the cells and/or prison. This prevent's data from getting into and out of the proson, to prevent the planning of an escape.
However, if a prisoner is reasonably smart, he would also have the blueprints of the prison on a harddrive on him, maby a hidden drive.
Now, I'd say, here comes the severeness of the crime into play. In my option it would be a total overkill to fry all the electronics, in one, that is arrested for alcohol abuse while driving.
How ever, how would you deal with such a situation? There are multiple ways to do so. The easiest would be to reset or whipe the hard drive. However, the disadvantage of this method can be, that the data could be recovered.
Or you could install a virus or some other malware and use ther tec for your own advantage. You know everything of everyone at anytime, vital signals... And the best thing is, you don't have any costs for doing so, it's completely free to use and comes built in with most prisoners.
Leave your creativity of the leash for further Ideas...