Hey, Zuckerberg—the Winklevoss twins see your Facebook and raise it a virtual currency trust. The Winkelvoss Bitcoin Trust, founded by brothers Cameron and Tyler, has filed with the SEC with plans to sell around $20 million worth of shares in the digital currency with each share representing a fraction of a bitcoin. The company behind bitcoins says the number being sold is capped at 21 million, and 11 million are currently in use. Recently online merchants and small stores have started accepting the virtual currency, while companies like Western Union and Paypal have expressed interest.