Fortunately, I've never had anyone move my bike on me, but I have often considered getting an alarm with a pager like the Gorilla or other models.
Once, I did find that someone had left half of a pizza, in a take-out box, on the seat of my motorcycle outside an Italian restaurant that I had been dining in. I brought it home and ate it for lunch the next day, and called my friends whom I'd had dinner with to thank them for it. They said "We never left a pizza on your bike - none of us even had pizza last night."..... Hmmmmm Well, at least I wasn't poisoned!!
