Googled/Wiki'd: laser tripwire, laser security, motion detectors, so forth.
So you guys have all seen heist movies, right? With the museum gallery or office or whatever that's protected by a laser security grid that needs to be disabled or dodged through. Hollywood loves their lasers.
My question is sort of multifold, since I really haven't been able to find much. Is this just a popular movie trope or are such systems actually in use in some places? (Wikipedia didn't list anything like it in their list of applications for lasers, but Google turned up a lot of how-to instructions for building them, so I'm not sure which to believe.) If they are a real-world thing, when did they first start coming into use, and would the layperson have been aware of them? And either way, when did the movie trope-- especially with regard to having an acrobat/gymnast/etc. to dodge through the beams-- start being used?