Going Clear: Scientology and the Prison of Belief

The frightening thing about Scientology is, that it has the brutality of some cult, founded by some nutjob, but at the same time a level of organization and international connections of the Roman catholic church.
What surprised me the most while watching the documentary, was how Scientology strongarmed the IRS into declaring them a religion. They make a ton of money, emotional and physical abuse people, even children etc. and are spared of paying any taxes. HOW IS THIS NOT ILLEGAL?
After all, that I heard about the practices of Scientology I think this documentary is a strong statement. Anyone who takes it up with them is immensely brave.