How does a magnet affect the flow of a video game

Inside every CD , DVD, and even Console drive, is a reader. This reader moves back and forth at fast speeds to read what content is on a disc. This reader is the a very small box with a lens on it. AKA its metal, in some parts. So when you use a magnet on it when its trying to read a disc, it will cause your reader to not move and possibly break. Using a magnet even on a computer or on any electronic device is extremely bad for the most part. In some cases can erase everything and even destroy parts from ever being used.