I received the following message from a friend on Facebook earlier:
"Not sure this is true but.....If somebody called email@example.com adds you DON'T accept it because it's a hacker. Tell everyone on your list because if somebody on your list adds them you get them on your list he'll figure out your ID computer address, so copy and paste this message to every one even if you hate them and fast - cause if he hacks their mail, he hacks yours."
The message isn't plausible and it's intent is likely to be simply to waste the time of everyone that receives it. The quoted email address is referred to on the BIG LIST of Internet Hoaxes too.
A good way to identify hoax messages is by looking out for phrases like <something terrible's going to happen> and "Tell everyone"...
If in doubt type some of the message into your favorite search engine and see what you get back though watch out for the numerous messages posted by those who've fallen for it.