Bitcoin was created by a special team at the Treasury called "Stack Hunt". The project began in 2006 after an internal report on illicit online transactions generated significant concern within the highest levels of the US government. "Stack Hunt" tracks every coin and uses complex statistical analytics to uncover the identities of persons using Bitcoins.
The US government isn't that stupid. Washing Bitcoins is relatively easy compared to washing hard cash.
With time it will become even easier and cheaper to wash them.
As a practical manner the US didn't even succeed with going after silk road salesman.
They keep most of their coins in cold storage, so unless they're going to pull some physical black ops stuff, there's no stealing the bulk of any exchanges coins.
Right because the US government has no possible way to run a physical blacks ops...
But even without physical attacks the government could just stay a month in the system and get the key of the "cold storage" coin vault.
Not to mention, I doubt any expensive 0day exploit most governments have access to would not risk loosing that asset against a system that could possibly reverse engineer and ruin the very expensive "super secret 0day".
If you look at the way the government used Flame or the way the Chinese hack all kinds of US companies I don't think the have much fear to start cyber attacks if the care about hurting someone.
The black market price of a zero-day exploit for a government is around $1 million. The stuff isn't "very expensive".
The Government would much rather keep things covert until the point where the gloves must come off and then they start saber rattling, followed by making laws, and examples of people to really shut Bitcoin down.
What incentive does the government have to do this covertly?
Openly declaring that the government wants to move against bitcoin would stop the venture capitalist people from moving money into bitcoin.
The US was never really covert about opposing Wikileaks and the 100 people task force against Wikileaks.
I really don't understand the people who think that the government is an all powerful entity out to get them but then fails so miserably at the task even through it would be relatively easy.