Wow, I would like to know what prompted this raid. Since they've been in business for 8 years, something must have happened to spark an investigation and subsequent raid.
The government was denied a motion to dismiss a lawsuit filed by the Liberty Dollar corporation against the Director of the US Mint and the Secretary of the Treasury on October 15, and had just filed another motion to dismiss an amended complaint a week earlier.
Why duke it out in court when you can intimidate and bankrupt your opponent at the stroke of a pen?
That's a lot different than just selling gold coins. The OP appears to have been selling securities and/or commercial paper (perhaps orders, notes, or some type of negotiable instrument). And the government should regulate those who sell securities and negotiable instruments. Because without government regulation, buyers get scammed and ripped-off. That's why the government regulates those activities.
Securities regulations cover a very specific list of instruments in the definition of "securities," and negotiable warehouse receipts - which is what the Liberty Dollar certificates are - are not covered under those regulations, but rather under the Uniform Commercial Code Article 7, with which the Sunshine Mint and the LD corp was in compliance, including monthly and annual audits of bullion holdings versus receipts outstanding.
Here's a link to the Washington State Department of Agriculture's form for requesting negotiable warehouse receipts, for example.
A warehouse receipt is a document of title, supported by legislative provisions. For example, see 7 USC 241 et seq for federal law pertaining to agricultural products warehouse receipts, or Title 69 Chapter 2 of the Idaho Statutes for bonded warehouse law that would apply to the Sunshine Mint in Coeur d'Aleine - in particular, 69-223.