These are all obviously dumb and we all do it.
People leave their valuables near their seats, when they go to the bathrooms.
People fall asleep with purses and money belts at their feet.
People put electronics in the overhead rack in rows behind them if others are full.
People do not lock their carry-on bags.
Oh dear so much to think about, but would we be so casual if we were on a train? or Bus?