How many times have received a petition from your friends, urging you to pass on a particular email or cell phone message, claiming to be a matter of life and death or of honor, or of social duty, or of what not, and you felt obliged to do what it said, and passed it on to ten more of your friends?
The subject may be anything under the sun a little Japanese girl was separated from her family in the terrible Tsunami a couple of years ago, and unless you help by sending the email with her photo to everyone you know, she has little chance of seeing them again. Can you be hard-hearted enough to resist the appeal? All it takes you is a few clicks, and it's done. Wouldn't you do that for a little fatherless child?
Or it may be about how these new line of cell phones made by a famous company are dangerous when used in a certain way. If you try to talk on them while the battery is charging, they sometimes explode and take your head off. Is any of your friends using this model? You had better forward this to them, just in case.
Or perhaps you can get this top-of-the-line computer just off the shelf and with all accessories attached, for absolutely free that is, if you forward this mail to at least ten of your friends. They are somehow keeping a watch on how many forwards you do.
And so on and so forth. All of it is fake, of course. There is no orphaned child whose fate depends on you. No cell phone is going to kill you friends through beheading. That doorbell you hear is not the delivery guys asking where they should place your shiny new computer, which you just earned through email forwarding.
Similarly, there is no flesh-eating banana, Tommy Hilfiger is not a racist, your friends and family are not at risk from a particularly lethal type of rat urine, an extremely poisonous South American spider has not infested all the toilet seats in the country, you don't need to tap the mirror with you finger in every public toilet you enter, etc. We could go on for hours on that theme. But the substance is that the continued existence or well-being of the world at large does not depend on your forwarding an email.
The whole email hoax system preys upon the paranoiac tendencies of modern urban human beings, and leverages the unconscious fear that something may go horribly wrong at any moment. We feel we aren't doing enough to justify our existence in the world, so an email of this type pokes your conscience and urges you to do something about what is happening to the world. It depends on our appetite for sensational news.
Do not fall into the trap of the email hoax; if you do, you shall only be furthering the cause of pranksters and spammers, in addition to wasting your precious time and bandwidth.