WHY DO DETENTION CENTERS TRY TO LIMIT CONTACT WITH PRISONERS?
They are afraid of Collusion, or con artists taking advantage of religion or friendliness over time to get favors they could not get otherwise. Inmates band together and may try to get an innocent person to commit a crime. It is a very serious problem but the need to rehabilitate the prisoner must be balanced against the need to protect by forcing total isolation from the outside world. For an excellent account of how collusion takes place, read Games Criminal Play.