>This sure seems like it would be a violation of a person's right to be secure from seizure of property in the USA.

The US government made a 50%+ profit by forcing people to sell their gold in 1933:

http://en.wikipedia.org/wiki/Executive_Order_6102#Effect_of_...

>Executive Order 6102 required all persons to deliver [gold] owned by them to the Federal Reserve, in exchange for $20.67 ... The price of gold from the Treasury for international transactions was thereafter raised to $35 ... resulting in an immediate loss for everyone who had been forced to surrender their gold ... The resulting profit that the government realized funded the Exchange Stabilization Fund