Not sure if this answer as posed in the title is sufficiently about law to be on-topic. If so, my question defers to the more legal alternative:
Is it legal for a federal prison to supervise the non-contact visits of their inmates?
This source seems to suggest so, though it isn't too explicit about the rules around non-contact visits; thus, I don't know if it refers to someone just watching the inmate in the visitation room, or if it refers to active (as opposed to passive) monitoring of the contents of their conversations.
