I think I should mention, the act shorting itself is legal, what is illegal is shorting using "non-existent" or "naked" short shares, which is what Hedge Funds like Citadel and Melvin Capital are currently doing, the worst part for them when it comes to both AMC and GME is that they can't drop the price too low as it will serve as an open invitation for people to accumulate more shares that the funds will have to buy back at a premium nor can they allow the price to go too high as the same thing will happen, they will have to buy them back at a premium.