The main thing I notice both in the comments on this question and in the responses is a broad and generalized attack on organized religion, referring to any organized religion as a "cult" Perhaps it is because I am a Christian, but I never believed my religion to be a cult. In my church, our pastors encourage the congregation to question anything we are told about religion and to come to our own conclusions about Jesus Christ, God, and the Bible. This is the case for nearly every church I've ever been too, we are given ideas to build off of, and are expected to question them before we either accept or reject them. I also know many Christians who disagree with one or more aspects of their denomination or faith. To my mind, a cult is a group that brooks no discussion of its beliefs or practices, doubt is bred out of the followers and questioning is discouraged. I thought a trademark of a cult was to demand absolute blind acceptance of every aspect of the group. It seems narrow-minded to classify any organized religion as a cult, simply because it has set beliefs and practices that are based on an unknown higher power.
As for the question at hand, I don't think scientology is dangerous, just vaguely ridiculous. (If rich people want to give their money to a religion created by a science fiction writer, well, it's their money.)