USA₮ is not legal tender (as described in section 5103 of title 31, United States Code) and is not issued, backed, approved, or guaranteed by the U.S. government. USA₮ is not subject to the insurance protections of the Federal Deposit Insurance Corporation (FDIC), the Securities Investor Protection Corporation (SIPC), or any other government agency.

I don't know why they are cautious when they are federally regulated!