This has been occurring for a long time in penny stocks. Outside 3rd parties selling unregistered stock is not new.
I was involved in such a company about 6 years ago. The tell tale sign is the volume based on the float. It was not uncommon to see half of the float turn over almost daily. On high volume days the entire float would change hands.
SNEY has a float between 600-800 million shares. We struggle to reach 1% of the float so I think the chance of involvement is really small. If we were seeing volume of several 100 million a day than I would be concerned.