Internal FBI risk assessment of Bitcoin network [pdf]
Nice document. It shows well the way of thinking of our governments."detecting suspicious activity, identifying users, 
and obtaining transaction records is  
problematic for law enforcement." - That must deeply hurts FBI people :)"Despite the virtual nature of Bitcoin, users 
value the currency for many of the same 
reasons people trust Federal Reserve notes: 
they believe they can exchange the currency for 
goods, services, or a national currency at a later 
date."People do not trust "Federal Reserve notes" (or any other official currency) - they are forced to use it, since they must pay taxes in it.But it is good, that at least some people realize that there is no such a thing like US dollar, only those "notes" printed by Ben Bernanke and his pals.If one day Bitcoin gets truly popular governments will be in trouble. How to tax that beast? I wonder if there is any other solution then poll tax.