The Liberty Dollar is a privately issued currency that aims to be an alternative to the United States dollar. It is based on an ounce of silver, with one ounce of silver being currently equivalent to 20 Liberty Dollars. The US Mint has expressed its concern about these issues, which has increased the demand and the commercial acceptance of the Liberty Dollars all over the USA. On 15th November 2007, the FBI raided the Liberty Dollar headquarters and seized most of their assets. Since that, these coins have become even more attractive to collectors.