I have recently found out that:
Concert laser shows, and other laser sources can, literally burn your DSLR sensor. The problem has not been very obvious for a long period of time, since we used to take only stills with DSLR’s, exposing the sensor for only a very short period of time. The shorter the exposure, the less chance there is that the laser beam hits the sensor at that very particular moment.
Now that DSLR’s are also capable of filming, the problem is appearing more frequently. While filming with your DSLR, the mirror of your camera is up, and the sensor exposed. Laser beams although often spreading over distance a little bit, are known for their very linear and small beam. This beam hitting the lens, then refocused on the sensor, can ruin your sensor at the very first hit.
there is a lot of documentation on the subject on the internet (search for ‘laser beam killing sensor’) but I think this single movie tells the whole story.
Someone filming with a Canon 5D mark II (a 2500$ camera) not aware of the possible damage that might occur. At the end of the song, his sensor is turned completely useless.
Beware if you care.
PS.: Share if you have other friends with digital gear, interested in picking up on a concert from time to time, … Same thing can happen to your video camera, and I suppose to your cellphone camera sensor too.