If there are any plans to illegalise cryptocurrency, they will destroy the coins. Sent to eater address oblivion, or recorded destruction of the private key... without revealing the actual private key in the process of recording the destruction? Is there are way of provably destroying a private key!?!?!?!?!?! Seems self-repudiating.
If there were plans to outlaw cryptocurrency in general, FinCEN of all government entities would be well aware of this and would not even bother promulgating regulations. The criminal complaint in the Ulbricht case itself emphasizes that Bitcoin has entirely legitimate applications, something I can't see them bothering to argue in a charging document unless it actually does reflect policy.
Things like illegal drugs are routinely destroyed, when not recycled for the purpose of controlled buys or other sting operations.
So far, the only public statement by the feds has been that they intend to liquidate the Bitcoin somehow. Even the snarky way they transferred the funds (324 FBI) seems to indicate whoever is handling them has at least some clue and a measurable sense of humor (usually lacking in feds).
I'm still sticking by my prediction that they'll get rid of the coins in a stodgy, old-fashioned way, like selling it all at once in an auction. They get as many weird objects by forfeiture as you see on one of those pawn shop reality shows, and that's how they usually do it. There are a number of smarter ways they could do it, but I'd bet they use their old standby.
