- they consume bandwidth or storage within the recipient's inbox;
- they force people to waste time sifting through the messages and possibly taking time to verify the information; and
- they spread hype and, often, unnecessary fear and paranoia.
There are two main types of chain letters:
- Hoaxes — attempt to trick or defraud users. A hoax could be malicious, instructing users to delete a file necessary to the operating system by claiming it is a virus. It could also be a scam that convinces users to send money or personal information. Phishing attacks could fall into this category.
- Urban legends — are designed to be redistributed and usually warn users of a threat or claim to be notifying them of important or urgent information. Another common form are the emails that promise users monetary rewards for forwarding the message or suggest that they are signing something that will be submitted to a particular group. Urban legends usually have no negative effect aside from wasted bandwidth and time.