$70k is about the price of locking up a single inmate for a year. Not a substantial expense for the corrections system.

There are substantial benefits to keeping the prison population entertained. Idle hands are devil's playground, as the old saying goes. Paying a few grand a month for TV may substantially reduce stabbings, rape, and other violence and disorder, all of which creates very serious costs for the inmates, the staff, and ultimately the taxpayer.

Reducing cable may actually end up costing corrections services more in the long run if security and medical expenses have to increase to compensate for a less docile prison population.

Or maybe cable TV is so terrible these days that corrections decided it was actually inciting more violence.

if it makes you feel better...they dont get to watch the free cable for very long.  since we dont have enough jails and prisons to house all the inmates...when new criminals go in we just flush a bunch of criminals back out into communities before their time has been served.   and since most of them are life time criminals, they leech off welfare for a month or two and then are back in jail - causing the release of other criminals.    

they have it all worked out...they more crime they commit the less time they all spend in jail.  its like pay it forward.