I used to drop my chain to discourage rideaways all the time. I used to do the "put it in high gear" method posted above also. Now I usually just go ahead and lock it.

Sometimes I do leave the Fixed gear Free Spirit unlocked out front of sbux just to see if some tweaker will try to ride off on it and crash but no takers yet. I don't think I'd have any moral qualms about laughing my ass off and possibly beating at least half the living daylights outta anyone that did crash my Free Spirit.

As for brake disabling, Seems like many bike thieves would know how to ride brakeless and if they don't there's a good chance your bike will be broken as the thief piles into something, so not that good a deterrent.