A prison programme brought in under the government of George Bush, the former US president, is under criticism.
It monitors the communications of prisoners who have been convicted of having links to terrorism.
All telephone calls, emails and visits are vetted.
The families of inmates say it is an unfair punishment for non-violent offenders, and a group of lawyers has joined their fight.
Al Jazeera's Kristen Saloomey reports from Terre Haute in the state of Indiana.