Not a lot. Mine's pretty much off road only and lives in a garage. On the rare occasions I do ride it around town, I stick a disc lock on and don't leave it anywhere too long. For what it's worth, kick starting a hi-comp, 650 single is a definite skill - rules out a lot of the random squids.
The Husqvarna 500 I had before, had no ignition and electric start - that was a bloody liability!