The Courts would not allow the bodies of the Resting Ones to be released from suspended animation as the important people would be in direct competition with those currently holding power. The ones in power simply manipulated the Courts to prevent the Resting Ones to be revived. The group then turned to stealing the bodies, risking summary execution in the form of hanging since body snatching was a capital offence.
Natasha Stengos and Grigory, who were part of the group, tried to steal back the body of Natasha's father, Arthur Stengos. They found that he was being turned into a Dalek by Davros. (TV: Revelation of the Daleks)