Not at all. It's a transfer of wealth.
In the US, when those coins are converted into a physical currency, (cashed out) that's when Uncle Sam gets his share. Getting an account to do so is no different than applying for a bank account. The current "Know your customer" stuff takes care of illicit activities like money laundering by identifying the person converting their BTC to USD. Not only is the person identified, their bank account and amount transferred is as well. One thing's for certain, when you convert BTC to USD Uncle Sam WILL GET his money.
Otherwise, the BTC is still an unrealized investment gain with no tax due.
I suppose if you were to transfer BTC to a Country that offers private banking transactions and cash out there you could get away with money laundering, but that's nothing new and certainly not limited to BTC.
And as a hypothetical, if you were to purchase bullion with BTC, there must be a shipping address to go with those purchase records, then you have to sell it. If I was going to set up some sort of illegal activity that I didn't want traced back to me I'd use cash, US dollars, like everyone else does. BTC leaves too many trails getting in and out.