So I read the warrant against Gox,
http://cdn.arstechnica.net/wp-content/uploads/2013/05/Mt-Gox-Dwolla-Warrant-5-14-13.pdf , and I think basically they are trying to justify the seizure by saying Gox is involved in dealing in currency and transmitting money for their customers, which Karpeles denied when he registered the account with the bank, however, I doubt whether such accusation is really well-founded.
First, the warrant is very assertive that Bitcoin is a digital currency, and Gox is a digital currency exchange, nevertheless, according to
http://www.ecfr.gov/cgi-bin/text-idx?c=ecfr&sid=d5570d7646c5fc13fe1fa42a61d1dcf1&rgn=div5&view=text&node=31:3.1.6.1.2&idno=31#31:3.1.6.1.2.1.3.1(search for "(m) Currency") Gox cannot be called a currency exchanger or dealer because it doesn't deal in foreign currencies, you cannot exchange dollars for other currencies on Gox directly, you can only exchange them for bitcoins, which is not a currency by their definition.(In fact, the Japanese authority considered Bitcoin a ledger and decided not to regulate)
Second, Gox cannot be called a money transmitter either, according to the definition from the same source(search for "money transmitter"):"(5) Money transmitter —(i) In general. (A) A person that provides money transmission services. The term “money transmission services” means the acceptance of currency, funds, or other value that substitutes for currency from one person and the transmission of currency, funds, or other value that substitutes for currency to another location or person by any means. " Especially the following two exceptions:
"(ii) Facts and circumstances; Limitations. Whether a person is a money transmitter as described in this section is a matter of facts and circumstances. The term “money transmitter” shall not include a person that only:
(A) Provides the delivery, communication, or network access services used by a money transmitter to support money transmission services
......
(E) Provides prepaid access; or
(F) Accepts and transmits funds only integral to the sale of goods or the provision of services, other than money transmission services, by the person who is accepting and transmitting the funds."
So my conlcusion is there should have been no need for Gox to register as a money transmitter, as they never engaged in exchanging one person's currency and funds for another person's, and Karpeles should indeed answer "No" to the two questions. Any legally knowledgeable guy please enlighten me if I am wrong.