I think a better policy would be requiring, as a condition of copyright registration, a copy of the multiplayer-related server and client code to the government

I think a better policy would be requiring, as a condition of copyright registration, a copy of the multiplayer-related server and client code to the government. If the public servers are shut down, that code is released to the public so anyone can run a server. You'd have to tailor the law so that they can't just keep a single, underpowered server up rather than release the code or whatever. But it might be possible to accomplish. That said, I'd rather copyright just didn't exist in the first place.