One would need a pretty smooth and accurate gimbal in order to keep the beam consistently pointed at the cockpit. Also, the a/c would have to be banked sufficiently in order to get as shot in the window.
I've "played" with lasers and agree that it's not an effective weapon when used as the article alleges. For the cost and effort involved, one could buy several MANPADS.
Having said that, I wonder if anyone has looked into if any shopping malls, movie theaters, or night clubs had searchlights or lasers set up to promote something?