misuse of solitary confinement has been widely controversial. in immigration detention centers, reports have surfaced concerning its use against detainees in order to keep those knowledgeable about their rights away from other detainees. in the prison-industrial complex itself, reports of solitary confinement as punishment in work labor prisons have also summoned much criticism. one issue prison reform activists have fought against is the use of security housing units (extreme forms of solitary confinement). they argue that they do not rehabilitate inmates but rather serve only to cause inmates psychological harm. further reports of placing prisoners into solitary confinement based on sexual orientation, race and religion have been an ongoing but very contentious subject in the last century.