This reminds me of an article in one of the motorcycling press from some years ago (about the time the Fireblade was first released).
After having his pride and joy stolen/and or vandalised from his garage 3 times in the first 9 months, with minimal response from the police, said owner decided to set a trap for the young scrotes responsible.
Leaving the bike slightly less well defended that normal, to make it irresistible to aforementioned individuals, owner and a couple of friends sit in the back of a van about 10 yards away. Sure enough, spotty yoof arrives, and takes a pop at the lock, at which point it's a case of 'out the van, grab the little oik, back into the van'
After 20 mins, a lengthy lecture and, quoting from print "a f*cking good kicking", the young chap was released and allowed to go on his way. Sure enough, word got around, and the owner's bike was never touched again.
Not legal by any stretch, but doubtless satisfying for the owner, and very very effective. This was some 12 years ago, and things clearly have not improved in terms of police response. How much longer, I ask myself, before this becomes more common as increasingly desperate owners attempt to protect their property?