>And somehow nobody has ever used this as an opportunity to kick everyone out, hijack the plane and crash it into a building.

Because how much damage could you really do with one of these, versus a widebody jet fueled up for a long flight?

Here's someone who crashed a smaller aircraft into an office building. It just damaged a corner office and killed the teenager who was at the controls, not exactly the kind of major attack that terrorists go gunning for.

http://en.wikipedia.org/wiki/2002_Tampa_plane_crash