As long as they are secure aren’t don’t give them unfettered access to the internet. Wouldn’t put it past some of the ones in jail for illegal hacking to find a way of breaking through any blocks to allow them to do so.
However, if it does facilitate them improving their education or skills then that is good is it not? Unless you are going to lock up every criminal forever it is better that they are given the opportunities to make themselves more employable in honest work when they leave than unleashing them back into society just as dumb and ill educated as they were when they arrived.
ANY access to the Internet should be denied. Those times when there was an underground “telegraph” of intent by prisoners who are plotting riots or prison breaks have been plenty enough of a source of misery, and access to the “dark net” would only multiply the problem much further, keeping the prisoners in touch with outside entities to control the flow of events from within prison walls.
Could you imagine the leverage this would give a MS-13 jefe or a Mafioso capo?
The odds are better than average that an inmate that has used his time to obtain a high school and post-secondary diploma in something marketable will probably do his best to not go back.
My preference is for paper, pen, and textbook. You remember more when you write it.
They have computer stations in the library. They don’t need personal tablets.