I lived 6 blocks from th headquarters in Clearwater for 5 years.
The main problem with Scientology seems to be their tax status. They're classified as a church, and pay no taxes. They also claim they are not a religion, but a way of life. They also earn billions of dollars a year, through book sales, auditing classes, and real estate ventures. Ridiculous amounts of untaxed income. They owned most of downtown Clearwater, and were in the process of doubling the size of the headquarters building. It covered 2 city blocks. Most members give LARGE amounts of their income to the church.
Most of downtown Clearwater was crawling with churchgoers. There would be 300 people with matching shirts standing on a corner, waiting for a light to change. They'd wander around, and never spoke to anyone. Ever. Very creepy. Of course, anyone who prays to an alien named Xenu probably wouldn't be much fun to talk to anyway.