How do SELF-ERASING videotapes work?

Yesterday I received a VHS videotape for a consumer research company. After I watched the tape (a pilot episode for a possible new TV show), I answered an online survey with my thoughts on the show.





The instructions warned me NOT to use fast-forward or rewind, because the tape had a special "self-erase" feature. As I played it, it was erasing itself as it went along. I verified this by rewinding it AFTER I'd watch the whole thing -- sure enough, there was nothing but "snow" where the show had been.





How does this work?? I thought the only way a VCR can erase a tape is if the tape comes in contact with the "record head" or whatever that mechanism is called. How can simply PLAYING a tape cause it to be erased? I'm wondering if maybe there's some special mechanism on the TAPE itself, that causes it to self-erase, and that the VCR has nothing to do with it. Anyone know? :)

How do SELF-ERASING videotapes work?
they work because there is a magnet inside, as you begin playing the tape as it begins to play and spool up on the other side it first passes by a magnet this magnet will erase the recording, u can avoid this by removing the magnet before playing the video
Reply:Yes, there is something in the cassette that erases the tape. It's probably just a magnet that the tape moves over just before the take up reel. That way, you see what's on the tape, but as it re-enters the cassette, it passes over the magnet which erases it.