federal prosecutor has right. it's written on the FINCEN law this thing....
a person that creates units of convertible virtual currency and sells those units to another person for real currency or its equivalent is engaged in transmission to another location and is a money transmitter. In addition, a person is an exchanger and a money transmitter if the person accepts such de-centralized convertible virtual currency from one person and transmits it to another person as part of the acceptance and transfer of currency, funds, or other value that substitutes for currency."
A court will decide who's right. I am not so sure.
"An exchanger is a person engaged
as a business in the exchange of virtual currency for real currency, funds, or other virtual currency."
http://www.theverge.com/2014/1/31/5364406/bitcoin-miners-investors-not-regulated-fincen-rulingThe FINCEN thingy was meant for businesses, not individuals (investors or traders). Since MSB licenses are very expensive, a broad application of these regulations would essentially result in a ban for individuals to trade Bitcoins.
Normally in the civilised parts of the world, courts tend not to restrict the rights of individuals too much.
The nasty part is to draw the line between business and personal activity.