The free market is an effective regulator. WPN knows if they use shady business practices it will kill their reputation and their company. There's their incentive to not cheat people and do the best work they can.
And if that's not good enough for you, how well did regulation work for Ultimate Bet, Absolute, and FTP? Regardless of regulation, there are just some businesses that suck. Once people accept that maybe they'll stop being so paranoid about regulations.