Anything is possible.  I love the argument that Bitcoin is the currency of the under world.  More guns, drugs, sex and other evil are paid for with the US Dollar, which is far more difficult to track. 

I would not put it past the government or the NSA to create it in an effort to track money movement. 

That said I don't believe that they did.  If they did why did it take an accidental find (fake passports) to bring down  Silk Road?  If they have the ability to track, but don't use it in an effort to not let it out of the bag then what good is it?