Whenever the Mythbusters pull out the neodymium magnets, they warn the viewers that they’re dangerous and not to be played with at home. But they’re only magnets, you say, and not that big. How dangerous could they be?
SuperMagnetMan (love the name) demonstrates in this video. The power of magnetism causes chunks of metal to take flight. The victims in the video: a ketchup packet, a lime and some grapes. The real danger, though, can be found on the Sciencepunk blog, which has all the evidence you might need, including an x-ray and a bloody photo, to convince you to be careful with these things.