Sometimes when travelling by plane you have to wait for some hours on some airport, and if you're like me you get a little tired when travelling. So how can you secure your hand luggage, to some extent, so that you might take a little nap or rest your eyes a little.
I'm assuming that you don't have access to those rather expensive lockers, or a private/corporate lounge with guards. It's just you and your bag, small suitcase or backpack. The solution should be good enough, so that if someone attempts to steal or access your bag, you should be alerted/woken by that action.
Bonus points for solutions not requiring extra tools or equipment, but just normal stuff you already have brought along. Although if the extra tool really aids in securing it, then please do suggest those as well!