Bitcoin tumbled back below $10,000 and dragged the rest of the crypto space lower after U.S. lawmakers grilled Facebook on its cryptocurrency plans, as political and regulatory scrutiny of digital coins intensifies. Bitcoin is getting battered... But Ethereum is leading the charge lower... While the trigger for the selling was not immediately clear, during the testimony, a U.S. senator said Facebook was "delusional" to believe people will trust it with their money.