It is never a good idea to point a laser at anyone, none the less a plane or helicopter. Situations like these have been on the rise since laser pointers have become more powerful and readily available. Pointed a laser at flying aircraft can cause enough distraction that the pilot could crash the aircraft.
In this video, three kids surely picked the wrong helicopter to point a laser at. The helicopter was a police unit and fully equipped with heat seeking technology via infrared, allowing the pilot to radio in to ground level officers and follow the kids every move under the cover of darkness.