like someone else said above, if it were your mom, you'd want to be able to talk to her. The thing with picking and choosing who can get what is that

1. the innocent who will be unfairly punished because of they were convicted
2. those who killed out of self defense or accident or trying to protect someone are also being punished

i can add more but those are who I think of. As far as rapists, I believe they deserve a different type of punishment other than just jail but that's not the issue here.

I know ppl who went to jail for murder and rape who were innocent, so perhaps my view is skewed.
But no one is lobbying for these ppl to have twitter or facebook or being able to do whatever they want.

But being able to email and send pics back and forth to your family/friends could provide some relief and rehabilitation to those who are in jail