Well, ensuring that no one sets up a Bitcoin network from their retrofitted computers in the privacy of their home is not banning Bitcoin, at least not a useful

Well, ensuring that no one sets up a Bitcoin network from their retrofitted computers in the privacy of their home is not banning Bitcoin, at least not a useful ban that we should care to enforce. If we can disrupt the network so that even criminals can't get ordinary people to 'pay' via the network, than it's for all practical purposes a ban. I don't agree that banning it is harder than bittorrent. It's dramatically easier. Bittorrent doesn't have global state, so there's no one place to strike. The entire Bitcoin network depends on global consensus, and therefore there is one place to strike. If it is weakened so that it shrinks enough (how many miners will want to mine for an illegal activity?), than 50%+1 attack will be trivial for a state actor.