Although I'm just casually following this BTC craze, if what I'm reading in the past few weeks about how it is traceable is actually true, then it may very well be that the government is very happy to see its continued use as they build up evidence, especially if its being used mostly for drugs as @Baron suggests.
In the past few months we have had a few hacking cases revealed, and in many of those cases, there was a fairly significant delay in this info reaching the public because the authorities enjoyed having the lead in terms of knowing about it, and being able to exploit/follow it, without everyone running away from it since it hadn't yet been exposed. I imagine that BTC might follow a similar path.
For the moment, BTC doesn't pose a threat to the USD or the IRS being able to collect taxes. So for the time being, the authorities are more than happy to follow along, collect data, and when the time is right to bring it to an end, they will, and then go about doing something about all the bad guys that have been implicated.
BTC is NOT traceable. There is nothing to hack. The Gov't can't stop it. That's the whole point of the encryption. Tom Lee explained it would cost billions of dollars to counterfeit just a single BTC. There is no benefit to do that. He explained you are better off hacking the Fed then BTC. And I disagree with Baron on the drugs. That is NOT what is driving the price but it might be driving the use. IF that were to be true, drugs are not inelastic. Meaning there are economic substitutes. If Heroin, priced in BTC becomes too stretched vs Heroin in Dollars, people will take the risk and transact the drug in dollars like they have for decades. It never stopped Pablo Escobar.