When an army of retail investors openly collaborate on messaging platforms to manipulate a stock's price, essentially a crowd-sourced "pump and dump," it falls under SEC enforcement. A retail investor can still be prosecuted for violating SEC regulations, such as using insider information, when trading.
This is yet another example of unintended consequences with regards to social media and its power to concentrate misinformation and incite mob behavior. I'm sure the vast majority of the people on Robinhood trading up Gamestop (GME) have no idea of the potential legal harm they may be exposed to, not to mention financial harm, even though the T&C's they signed on opening their accounts (especially margin accounts) almost certainly spelled out those risks.
Robinhood business model is the canary in the coal mine.