Some are and some aren't. You have a lot of opportunistic criminals who see this as a way to make easy money and where the punishment is quite lenient. There's also evidence to show that the Rizzuto family in Montreal has ties to telemarketing fraud and that the Hells Angels has had ties to telemarketing fraud. Then you have Nigerian crime groups doing telemarketing fraud as well. So yes, there are the well-established groups that are backing these. At the same time, you have a lot of opportunistic criminals who are getting into this just simply because it's easy money.
