I thought their dwolla acct was seized due to non MSB compliance in the US which Mark lied about over a year ago about.
Did Mark ever claim MtGox was MSB compliant in the US? They relied on Dwolla, which is (or claims to be) and banks (which are). Then DHS came about and declared Mutum Sigillum a threat to USSA homeland security due to some technicality in how MtGox transfer USD to and from Dwolla. See:
http://numismatics.pwnz.org/15may-dhs-seizure-of-mtgox-funds-held-by-dwolla/