Some of you may notice that its possible to download movies etc using winmx and many are marked CAM, this refers to how the movie was obtained, usually the work of someone with a video camera recording it in a cinema, better quality versions are made from DVD rips but those are not usually available when a movie premiers.
Recently the MPAA have been showing off some prototype measures to prevent this sort of activity
http://news.bbc.co.uk/1/hi/technology/5097774.stmA device that could foil movie pirates who covertly record films in cinemas has been developed in the US.
As the reflected light is travelling in a straight line from the CCD, it allows the computer system to accurately pinpoint the location of the camera.
Once found, the system floods the CCD with white light from a projector to "blind" the camera.
"The biggest problem is making sure we don't get false positives from, say, a large shiny earring," said Jay Summet, a research assistant at Georgia Tech who helped build the device.
"We need to make our system work well enough so that it can find a dot, then test to see if it's reflective, then see if it's retroreflective, and then test to see if it's the right shape."
In the future, the researchers believe the system could use infra-red lasers and photo-detecting transistors, rather than cameras to search for CCDs.
They also believe that a real-world version would probably use a laser to "blind" the image sensor.
At the moment, the team is close to developing a commercial system that neutralises still cameras.
Still cameras are easier to spot than camcorders because their CCD is closer to the lens and there is less interference with the reflected light
An interesting idea, one that of course is open to countermeasures by the pirates, I think this will be at least a year or two away before hitting the cinemas in a big way as even I know a simple lens filter would prevent this technique being used, light passing through inwards is attenuated and passing back out by reflection would be attenuated again, hardly requires einstein to show the flaws in this system.