There are coins, but there is also paper money.
http://www.libertydollar.org/
The $10 Peace Dollar is a legal functioning currency dedicated to stop the war. As a private voluntary barter currency it can be used anywhere it is accepted.
...and then later...
Recently, Liberty Dollar sued the US Mint to compel the government to cease claiming voluntary use of the Liberty Dollar as barter is a federal crime. No Liberty Dollar, Ron Paul Dollar or Peace Dollar is claimed to be "legal tender."
So they say it is a legal currency, and then say they aren't claiming it to be "legal tender". That seems like a pretty transparent lie to me.
18 USC Section 486
Whoever, except as authorized by law, makes or utters or passes, or attempts to utter or pass, any coins of gold or silver or other metal, or alloys of metals, intended for use as current money, whether in the resemblance of coins of the United States or of foreign countries, or of original design, shall be fined under this title (!1) or imprisoned not more than five years, or both.
AMENDMENTS:
1994 - Pub. L. 103-322, which directed the amendment of this section by substituting "fined under this title" for "fined not more than $2,000", was executed by making the substitution for "fined not more than $3,000", to reflect the probable intent of Congress.
Seems pretty clear to me why the coins, precious metals, and the minting equipment were seized.
You are welcome to disagree with the law, but if you don't want your property to be seized, don't overtly use it in the commission of a crime.
Their complaints about the paper currency being seized seem pretty ridicules. They are claiming that that paper currency is backed by precious metals, and basically represent ownership of a corresponding amount of precious metal. The precious metals have been seized. It they were to try to do anything with the paper currency, it would be fraud.
You’ll love this one.