Bitcoin, the virtual currency libertarian geeks expect us all to use to pay for pizza in the future, has had a rough few weeks. A series of booms and busts have sent shivers down the spines of Bitcoin enthusiasts. Now, Gawker has learned that a much-hailed partnership between two of the most prominent players in Bitcoin, Mt. Gox and CoinLab, has devolved into a nasty $75 million lawsuit, which appears to be by far the biggest Bitcoin-related lawsuit ever.