Chain letters all have a similar pattern. From the older printed letters to the newer electronic kind, they all have three recognizable parts:

• A hook
• A threat
• A request

First, there is a hook, to catch your interest and get you to read the rest of the letter. Hooks used to be "Make Money Fast" or "Get Rich" or similar statements related to making money for little or no work. Electronic chain letters also use the "free money" type of hooks, but have added hooks like "Danger!" and "Virus Alert" or "A Little Girl Is Dying". These tie into our fear for the survival of our computers or into our sympathy for some poor unfortunate person.

When you are hooked, you read on to the threat. Most threats used warn you about the terrible things that will happen if you do not maintain the chain. However, others play on greed or sympathy to get you to pass the letter on. The threat often contains official or technical sounding language to get you to believe it is real.

Finally, the request. Some older chain letters ask you to mail a dollar to the top ten names on the letter and then pass it on. The electronic ones simply admonish you to "Distribute this letter to as many people as possible." They never mention clogging the Internet or the fact that the message is a fake, they only want you to pass it on to others.

Chain letters usually do not have the name and contact information of the original sender so it is impossible to check on its authenticity. Legitimate warnings and solicitations will always have complete contact information from the person sending the message and will often be signed with a cryptographic signature, such as PGP to assure its authenticity.

(Originally from http://ciac.llnl.gov/ciac/CIACChainLetters.html [link broken]).

-- Andy Pryke - 16 Jul 2001