[celticninja]

yeah but those are much more easily controlled, there is no controlling bitcoin once it is out in the wild.

If it was an NSA project to catch, say terrorists, well first they have to wait for bitcoint o get enough traction for it to be worthwhile being used by terrorists, then you have to factor in the amount of work required to identify those terrorists and that you may actually enable terrorists that would otherwise have failed to get funding i.e. you assist in terrorist plots more than you identify terrorists from it.