Originally Posted by bemoore
That's true, but I would think it much less likely that someone would have available a lock AND cable. AND, it would take much more time to attach another cable vs just adding another lock. Yeah, it's still a risk, but I think the risk is much lower. But in any event, I don't know anything (other than never letting your bike out of your sight) that would prevent someone from putting on another cable.
Simply put, If your bike is registered with the police, and somebody double locks you, phone them, explain.
They may come and chop it or just phone someone to bring a hacksaw, sit yourself down and start cutting.
Report first-cut later. My bikes reg, and I have had them come and cut a lock off my ex-wifes bike when I spotted it downtown. Reported stolen, they had no probs with cutting the lock, she showed up and rode away.