This New Yorker article has one of the most concise breakdowns of what is wrong with Scientology I've ever read... and it's still 26 pages long:
Read it. The whole thing. Save it. Scientology is a world-wide cult with real power and influence, and Haggis is exactly right when he says that he'll be discredited; very bad things happen to those who attempt to expose negative materials about the church.
I'm stunned by how incredibly effective the church is at keeping people once it has them; deny children education, extort incredible amounts of debts from hazy sources, constant repetition of dogma, escalating systems of "privileged secrets", separation from family and friends, hazing to excess, the creation of a veil of jargon over basic human behavior in order to mask simple questions (like, "Does this make sense?" or "Is it true?"), all of it spanning decades so that a dedicated member is literally stripped of any means for making a life outside the church. These things are abuses, but they're also well-known techniques for training social creatures into obsessive approval-seeking behavior.