Here is some information though Darkness:

https://en.m.wikipedia.org/wiki/Internet_in_prisons

Also, if you are willing to do in depth searching on google, you will find states that are furnishing prisoners with tablets for the purpose of connecting to the internet. Some states require the prisoner buy it for a small fee, others just give it away. Last I checked that was about 12 or so states but most will allow some kind of connection even with no tablet if supervised.

I hope that helps.