on balance, i think it's too late to make Bitcoin illegal or even put sharp restrictions on it here in the US.  

mainly b/c it's global and their are too many large, legitimate US investors involved already.  think NYSE, NASDAQ, multiple hedge funds, banks, VC funds, and numerous financial luminaries and Wall St folk.  just about the entire Silicon Valley wants it as fintech has been irrationally and unfairly excluded from financial innovation forever.  this is their time.  Wall St has begun to sense the inevitability and are climbing aboard.  there are plenty of overt data points and pending signs.