If someone came up to you on the street and stuck a gun in your ribs and said, "give me your wallet!", would you feel duty-bound to tell him about the $1,000 tucked in your sock as well?
How are you bound to tell a government thief what you would not tell a common street thief? If a common street thief has no right to rob you, why would anyone else?
Google " I'm allowed to rob you" by Larken Rose for a good illustration of the absurdity of believing anyone has the right to rob others.