Macrovision
A sneaky video copy block that messes up your VHS if you try to record from two machines at once. It's like the video world's version of a mean teacher.
"I tried to copy this movie, and my VHS started giving me a pop quiz.", @VHSFanatic99
"Macrovision is like the video world's version of a grumpy teacher.", @DVDHater42
"My VHS started acting like it had a grudge when I tried to copy this movie.", @RecordedRage"