Last week, Jennifer Shasky Calvery, Director of the Financial Crimes Enforcement Network (FinCEN), held a press conference to discuss about some concerns related to virtual currencies.
FinCEN is a bureau of the US Treasury Department, and reports to the Office of Terrorism and Financial Intelligence.
You can read her speech here and draw your own conclusion from it.
From my point of view they keep trying to relate the cryptocurrencies with terrorism and criminal acts, in a clear attemp to scare and frighten the citizens so they avoid the spread of the virtual currencies. They want to keep the monopoly over printing money and they know they could loose it if the digital currencies would grow too fast.