Interesting, but what sort of action would this be?
I'm not sure what Tuck had in mind, nor am I any lawyer, but the basis should probably be something like the "innocent owner defence" in asset seizure.
See: 18 U.S. Code § 983 - General rules for civil forfeiture proceedings
http://www.law.cornell.edu/uscode/text/18/983d) Innocent Owner Defense.
(1) An innocent owners interest in property shall not be forfeited under any civil forfeiture statute. The claimant shall have the burden of proving that the claimant is an innocent owner by a preponderance of the evidence.
(2)
(A) With respect to a property interest in existence at the time the illegal conduct giving rise to forfeiture took place, the term innocent owner means an owner who
(i) did not know of the conduct giving rise to forfeiture; or
(ii) upon learning of the conduct giving rise to the forfeiture, did all that reasonably could be expected under the circumstances to terminate such use of the property.
Each "innocent owner" would then have to file a motion with the court, yet s/he must have legal standing in order to do so, and be represented by legal counsel.
It's a little confusing, because the agency behind the forfeiture is supposed to give notice, and any person losing the property have time to answer. With a "gag order" in place, this process sounds problematic at best.
It does not seem possible for a putative seizure of Mt. Gox's bitcoins and cash to have taken place without at least tacit, if not full, cooperation of the Japanese authorities. Perhaps the laws in Japan are rather different.
This whole affair is certainly not in the best interests of Japan's reputation as an attractive investment destination, since no investor would ever wish to be subject to any such government confiscation.
It seems to me it would be easier to conduct a freedom of information act request on information regarding Mt. Gox's customers Bitcoins. This information should not give away anything about ongoing criminal investigations and should be accepted. It would simply request different bureacracies such as the FBI or other likely involved agencies to release information as to the whereabouts and/or ownership powers over customers' Bitcoins. Gets rid of the step of a legal case against the government which could take years.
After the request gives back information you would know whether the story is true or not, and the government would be able to continue its investigation, so it should be an easier way then forcing it to court from the get go.