Have you heard of that trick where you throw the dog a steak? One guy broke into someone's home, and stole a lot of valuables, and stole the Rottweiler too!

My intuition is that using strong locks like U-locks, attached to something solid, will mean that each bike would require minutes to deal with. I don't think criminals want to spend long periods of time in a house.

I've been thinking of this problem too. Perhaps a cement block with a heavy metal "U" sticking out of it.