The hallmark of almost every Internet hoax is that they tell you to forward the letter to as many people as possible. If you ever see such a message, you can be sure that it is a hoax.
Some of the hoaxes are harmful. For example, there is one attacking "Hanoi Jane" Fonda. It contains supposed quotes from famous prisoners of war who say they saw Jane Fonda participate in atrocities. However, the quotes are all fake. The real people exist but they did not say those things nor did they see Jane Fonda doing the things they supposedly saw.
Here are a few famous hoaxes:
The Dying Child who wants to get into the Guinness Book of World Records for collecting the most business cards. (Hint: 11 years have passed and the dying child is still alive. Somehow, the ornery critter just cannot be killed off.)
The commencement speech by famous author Kurt Vonnegut where he repeatedly advises to use sunscreen.
Bill Gates and Walt Disney will give you $5,000 for forwarding this e-mail message.
FBI covers up the fact that a Navy Missile shot down TWA Flight 800.
These are just a few of the common hoaxes. I have received in some form all of these within the past year, except for the one about a corporate official who was murdered just after sending me his last e-mail message.
To my credit, I never fell for any of them, but my friends who forwarded them to me certainly did.
There are many sites on the net which keep track of these hoaxes. Here are a few of them:
Sam Sloan