Why should MtGox, operating from Japan, follow USSA laws instead of Japanese laws?
Japan is more restrictive than the US in some ways. Until recently, you couldn't do anything with other people's money unless you were a bank. As of 2009, there's the "Payment Services Agency" classification, but that requires registration and audits too. Most cell phone companies in Japan are now also PSAs, so they can send money to and from phones.
Does USSA law apply to all bitcoin exchanges because what?
Only to ones which deal with US persons.
SEC rule: "Foreign broker-dealers that, from outside of the United States, induce or attempt to induce securities transactions by any person in the United States, or that use the means or instrumentalities of interstate commerce of the United States for this purpose, also must register. This includes the use of the internet to offer securities, solicit securities transactions, or advertise investment services to U.S. persons."Whether Bitcoin is a security is an interesting legal question. One lawyer argues
that Bitcoins themselves are not a "security" under US law, but he writes
"The securities definitions outlined above might not apply to Bitcoins themselves, but they are flexible enough to apply to Bitcoin exchanges that convert a Bitcoin to real-world currencies." There's a long history of investment-like schemes crafted to get around SEC regulations. There was, of course, Trendon Shavers' Bitcoin Ponzi scheme. There was a scheme to sell paving stones from Australia, a scheme to sell fractional shares in fruit groves, and even
psychic stock predictor. All were found subject to SEC jurisdiction. Companies in China
have been fined by the SEC. Being outside the US doesn't help if you do business in the US.
Realistically, if it works like "Customers deposit money and can't get it back", some financial regulator has the authority to bring the hammer down. The US SEC and the Japan FSA have a formal cooperation agreement.
MtGox has never been accused of operating as a money transmitter in the USSA. Mutum Sigillum was. You should read the warrant. Have you ever read anything about law, or just pretending?
That's FinCen. They're concerned about money laundering. The SEC is concerned about ripping off investors.