Rodger has what is probably the most [extensive blog post] on the subject, and it even includes a timeline.
Rodger writes:
November 9. Flight crews on four aircraft in the vicinity of Houston International Airport observe a green laser light shining into the air near the Conroe, Texas area, about 25 miles northwest of the airport. |
The [Cleveland] Plain Dealer article suggests that such incidents have become quite common in recent years. "The Federal Aviation Administration has found hundreds of cases in which lasers have been pointed at planes since 1997, according to an agency report. In April 2003, the FBI said in a report that lasers are being pointed at planes 'at an alarming rate.'" Speculation about the incidents has been escalating, especially regarding the types of lasers being used. In the recent Cleveland incident, the pilots reported a green laser beam, suggesting that it could something as simple as a laser pointer like this, or this. (As one ad says, "the intensity of the green beam is unbelievable, so powerful it can project a beam up to 3000 meters or 10,000 + ft. even under lighted conditions.") Other possibilities include commercially-available lasers for surveying and construction. A more frightening scenario is that terrorists may have obtained a Chinese-produced ZM-87 laser blinder which is specifically designed to blind eyesight. The Japanese terrorist cult Aum Shinrikyo—which launched the infamous Sarin gas attack on the Tokyo subway system in 1995—was discovered to have experimented with the use of lasers as weapons.According to The Asian Pacific Post, "Cult members apparently obtained laser design information from Russian institutes they visited and built a laser weapon mounted on a truck. They had planned to use the laser against Tokyo policemen, but the plan failed when the laser malfunctioned during the testing stage." |
If it's true that terrorists have gotten their hands on military lasers, it's possible that they haven't used them yet. Many of these incidents might be attributed to practice runs before they actually try to use the big guy. But the only real problem with that idea is that they somehow have to get the military laser into American and into their hands without the U.S. knowing about it.

Rodger points out that the lasers themselves can't actually do much to a pilot or the plane. But he later notes that Michelle Malkin, appearing on Fox News, suggested that the lasers might be used as trainers for ground-based systems. Perhaps so, but there's a lot of issues at hand. Unguided systems like an RPG-7 (which is only effective to roughly 1,000 feet) would actually require you to lead the airplane, the size of the lead being dependent on how far away from the plane you are and how fast the plane is traveling.
Question: why would the terrorists target airliners for mere explosion? What terrorist would be happy following up 9/11 with "simply" destroying an airliner? I'm not trying to minimize the importance of a destroyed airliner, but one airliner wouldn't live up to the "glory" they achieved from the 9/11 attack. That leads me to believe that IF the lasers are terrorist related, and IF the terrorists are planning an attack, then the attack will be big. The only way I can see them making a major-attack, based on that, is to try to bring down multiple planes all in one night.
Mind you, this is all conjecture. The other likely explanation is that a bunch of no-good teenagers got their hands on lasers and are farting around with them by shining them at helicopters and planes. Of course, that doesn't explain the recent, pre-news story upturn in laser "attacks."
If you can learn one thing from this post, learn this: almost anything anybody says at this point will be no more than conjecture.
If anybody else has any ideas, feel free to share, because I'm still trying to wrap my brain around this one. So far, I'm not that worried.
UPDATE: Another [good post] from Rodger. I agree with him that this is improbable behavior for Islamic terrorists. That doesn't rule it out, and it doesn't rule out an attack by another group either.