Names and faces to bikes

i swear some1 could just undo the rear wheel with a spanner and then walk away with the rest of the bike? ok it would look obvious but i have seen it done before....

You're right - they could actually walk away with the bike even without cutting through the wheel. They could simply squash the wheel into an elongated oval shape then pass it through the rear triangle of the frame, leaving the wheel attached to the lock and the frame completely free.