Robinhood is what all the people jumping on the bandwagon used. And this coincided with a sharp price drop on all of these stocks blocked. The reason was "Due to ongoing volatility", but any trader will tell you volatility is how money is made. It took all of the normal people out of the game, and tried to scare them into selling so that the ones holding the shorts are in a better position.

And to add to that, a company (Citadel) that pays Robinhood a large amount of money for their data is one of those with the short positions. So Robinhood itself has a stake in this.

Disclaimer: I have no idea what I am talking about and this is only my opinion.