Fork While Fork

I thought that by now, everyone knew that running random code was generally a bad idea. No matter who it's from, or where you found it. If you don't understand it, don't run it! Somehow, this always seemed self-explanatory to me; if someone says "Hey, run this!" the logical follow up should be "What does it do?" or, even better, do some research before running it! Well, I was wrong. Not so self-explanatory.