Hypothetically: What if someone contacted the police and used the words "Money Laundering" and "Silk Road"?
That'd wake them up...
I suspect that your local county police department isn't who investigates racketeering, money laundering, etc. I'm quite sure that the bodies who
do investigate such matters would have anonymous tip-off procedures in place. That said, because of resource constraints there's probably a threshold for investigation - either a dollar value or the possibility of connection to bigger operations.
It's known that certain US agencies are aware of the potential for Bitcoin to be used for money laundering, so it's possible that they would investigate any allegations in an effort to forestall Bitcoin becoming an entrenched method of money laundering (most financial intelligence services monitor emerging money laundering threats). If the IRS in the US is anything like the Australian Taxation Office, they investigate pretty much
all allegations of tax evasion.
There's inevitably going to be an investigation into a criminal use of Bitcoin sooner or later. There's no real way to tell what particular venture will trigger that and whether it will be initiated externally or by pissed of Bitcoin users who've lost money and are seeking retribution rather than restitution.
