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?
Amen bro. A very bad idea.