Microwaves are a wonderful way to heat up a whole bunch of stuff. But they don't work for everything.
For instance, you should never microwave metal. Everyone knows that one. But not everyone is aware of the destructive awesomeness that results from heating up soap, or ping pong balls, or toothpaste. Well wonder no longer, because BuzzFeed has a video run down of 16 Things You Should Never Microwave.