Well, what you do if you find a fiat pyramid scheme or a ponzi one. Prob you will warn everyone you know to not invest and stay away from it. Here you need to do the same.

The people need to be educated to not go into these schemes and with an effort from those reporting the schemes they found eventually it will stagnate.
There is nothing much the authorities can do, since most of the time (like 98%) the person behind the scheme it's not known.