Easy, they can destroy bitcoin the same way they destroyed bit torrent... Oh wait... Yeah, better shut down the Internet then.
That's a false comparison if you are honest.
First bittorrent is by a huge amount more decentralized than Bitcoin, and the decentralization of Bitcoin is shrinking, not growing.
Second bittorrent does not depend on frictionless integration with the traditional banking system like most of exchanging of fiat currency for bitcoins does which is what gives them there current exchange price.
It's unfortunately fairly easy to at the least significantly diminish the value of bitcoins and the use of Bitcoin if not out right destroying it by simply legislating it away. You forbid banks to accept funds coming from businesses dealing with bitcoins and label those few left who'd still do the mining as terrorists and hunt them down.
Of course when I say fairly easy I'm talking about the effects of such legislation not the difficulty of passing it all over the world and have it stick.. but this is something we will find out because there's not a shred of doubt in my mind they'll try to legislate it whether as an outright attack or in an attempt to control it.
