Don't mean to cause parnoia (it does strike deep, however!). I am not paranoid and really don't worry about such things. But when at large biker events and bike is unattended, well, that is realy easy pickings.
Buddy of mine on Softail was eating breakfast at Waffle House in Nashville right near Opryland (not a bad part of town at all) and some scumbag opened his saddlebag and took his notebook computer (not much security in those leather bags I know) and took his entire T-Bag off his bike with all his belongings.
I agree that if someone really, really wants it they will get it but we can sure make it a little bit more difficult.