Will certainly make for an interesting documentary.
Apparently Louis Theroux has been working on a documentary about it for quite a while too.
Was listening Joe Rogan's podcast with him and they were discussing how the Scientology cult first seems to get all the dirt they can on someone (under the premise of confessing sins type of thing etc.) then they can use that to blackmail people when they threaten to leave. I hadn't considered the obvious cases like Tom Cruise and John Travolta where it looks like they were threatened to be outed as gay to keep them in the cult.
Louis Theroux discussing it here from about 2:31:25: