These always have been, and always will be illegal. The difference now is the SEC will be hunting you down and fining you/placing you in jail. I'd recommend not joining these, because they're shady as hell, illegal and you'll be left holding the bag.
Good that "the SEC" has power over nomore than 4 % of the worlds population. I suggest that they build bigger prisons so that they can also hunt down poker players, sportsbetters, slot machine addicts etc. First of all though, they should stop short and margin trading. That´s the only thing where the mechanics can send you out with actual debt. Now THAT`s what I call shady.