Who are they to teach us?

God Men aplenty in our country. Jaggi Vasudev,Ravishankar,Aasaram Bapur,Nityananda and the list goes on. Their sermons are full of jargons.They dont practice what they teach. In spite of this you see vast multitudes attending their meetings and craving to meet them in person. Who are they to teach us? Each one of them has a murky past. Am disturbed. I know a couple of entire families who are devastated by these Gurus. What is the secret behind this.