I have never had anything taken from in or on a motorcycle. Radar detector, GPS, often my carry handgun is locked in a saddlebag (I do remove the magazine whenever I must leave it) never touched, and I park in some....interesting places.
It's interesting to note that for years and years all I ever drove were Jeeps. An Commando, three CJ5's, two CJ7's, and an YJ. As soon as the weather hit 60* in the spring the tops and doors came off until fall. I can't count the number of times that someone went thru the unlocked storage compartments.
I kept tools/snatch straps/gloves/etc in a lockable box behind the rear seats, but the glove box and center console were always gone thru with misc papers and such disturbed or spread around.....
....came out of a bar one time at closing and there is a drunk guy sitting in the shotgun seat. "Take me home" he yells, I played **** dragging the douchebag out of my ride. If he'd asked rather than just hopping in and demanding, he might have gotten a ride. Instead he got, lets just say "ejected".