I was just visiting Japan and many bikes have the rear tire O-Lock refered to. However, the lock was permanently mounted to the bike frame via lugs like rack mounts. Common item there so the bikes are made with the lugs. I saw the O-Locks in a store but did not get one since our bikes do not have the lugs built in.
The O-Lock would not stop a thief from carrying off the bike. I think the theory (in Japan) is that a legal owner would not be carrying his bike thus he must be a thief...and would get stopped by people in the area. I doubt that would be the case he in US.