* Most facilities have really crappy electrical systems, so they are restrictive about appliances.

* Many appliances can be great hiding spots for drugs, makeshift weapons, etc - in Texas all of the allowed appliances were clear for this reason, and had to purchased from the prison

* Paranoia about Internet access (yes, I know a typical laptop can't connect, but try to get into the mind of undereducated, paranoid staff that has to answer to a frightened public)

* Use of computers for illegal activities in prison - like gambling rings, etc - anything in prison is searchable, and paper is inherently more searchable than GB of texts for low-end guards)