A story went out a few days ago suggesting that the laser incident was the work of a man playing with his children, who didn't realize that his laser could interfere with air travel. But apparently he wasn't the only culprit. From [1] AP, with thanks to Jeffrey Imm:

NASHVILLE, Tennessee (AP) -- Federal officials are investigating an incident in which a laser beam was aimed at a jet after it left Nashville International Airport bound for Chicago.

Pilots of a United Airlines flight heading to Chicago's O'Hare International Airport on Sunday reported seeing a green laser beam shortly after takeoff, said United spokeswoman Robin Urbanski....

Federal agents are looking into similar incidents involving lasers and aircraft, including cases in Cleveland; Washington, D.C.; Houston; Colorado Springs, Colorado; Medford, Oregon; and Teterboro, New Jersey.

Laser beams can temporarily blind or disorient pilots and possibly cause a plane to crash. Federal law enforcement officials have said there is no evidence of a terrorist plot involving the laser beams.