Go here

http://securityforbikes.com/anti-pinch-pin.php

and be amazed at the Anti-Pinch Pin.

I put mine through the hole in the frame beneath the swing-arm pivot.

You can also put it through the hole in the rear hub, which is what it was designed for.

You could even use one as a wall anchor, assuming you can get inside the house wall, drill a 22mm hole, poke the pin through and use a second lock on that end of your chain.

With that lot, nothing is going anywhere short of a JCB or a porta plasma cutter!

Brian (who rests easy at night with that lot on guard)