"Looks like the majority of responses so far are from FReepers unclear on the concept of "property"."
That was a little oblique. Are you saying the government was justified?
Because I am. The owner cannot provide a legitimate provenance, therefore likely came by the coins nefariously--either actively or indirectly. Liken it to Holocaust booty which has taken a half century to recover, for descendants. Just because someone has something of value in his possession for a long time, doesn't mean that it becomes his, at some point. Time actually has no meaning, if it was taken.