Ban != Access
You can NOT ban someone from the Internet but you may deny access to Internet in prisons.
You can NOT ban someone from the Internet but you may deny access to Internet in prisons.
I think this would be relevant to someone who has committed a crime using a computer and remains banned from using the internet even after finishing a prison sentence (like the kid in the movie Hackers). It doesn't sound like that can happen now.
Suppose someone is caught with an internet phone in jail and is hauled in front of a judge. If it's banned, then they can have their jail term increased.
"Access to the Internet" is the right. Not the tools to access the internet.