Hey... just read this on another site...
12 Ways to Prevent Motorcycle Theft - Tech Review - Motorcycle Cruiser
Make Some Noise... Alarms may seem like a good way to attract attention to the fact that someone is attempting to purloin your bike, but in most places we have gotten so used to false alarms that people don't investigate or even bother to look. But everyone pays attention to sounds of destruction—such as breaking glass.
A large stack of beer bottles with a trip wire makes a sound that everyone will investigate when it gets tipped over.
Makes sense to me... and I usually have a least a small stack after settling down for the evening!