For what it's worth, I own one of the green variety - it's great for
pointing out starts etc at night.

My feeling is that if someone shined in the cockpit from (at least) 1 or 2
miles away, ...

(a) It would give me a bit of a fright - be damned annoying, but not
damaging - possibly causing a precautionary go-around at worst.

(b) Being that the beam is visable, it should be possible to give a
pretty accurate description of where it came from.

(c) Unless you mounted it mechanically, it would be pretty hard to keep
it shining in a cockpit.

Given the current talk on the topic I'm tempted to setup a controlled test
(with an additional safety pilot) where I'll get someone to shine it at me
(perhaps from the tower) during an approach in a GA aircraft.