Munging is the deliberate alteration of an e-mail address on a Web page to hide the address from spambot programs that scour the Internet for e-mail addresses. Such addresses are easily recognized because they contain the @ symbol. Address munges should allow a real person reading the content (as opposed to a program scanning it) to easily deduce the true e-mail address.
Here is an example of a munged address: editor at whatis dot com.
Munged e-mail addresses can be useful in Web sites, e-mail correspondence, chat rooms, and postings to newsgroups and special interest groups (SIGs). However, some experts advise against the practice because it may violate the Terms of Service (TOS) of the subscriber's Internet service provider (ISP). Munging should not be used if a response to a particular correspondence is desired. For example, when making an online purchase, the seller typically asks for an e-mail address in order to send a confirmation. If the address is munged, the confirmation will not reach the purchaser.
It is important that munged e-mail addresses not be mistaken for legitimate addresses belonging to third parties. If an innocent person, corporation, or institution is harmed as a result of a munged e-mail address, civil or criminal action could result. Fake usernames or domain names are particularly dangerous in this respect.
The term munging probably derives from the acronym mung (pronounced just as it looks), which stands for "mash until no good." It may also derive from the hackers' slang term munge (pronounced MUHNJ), which means "to alter information so it is no longer accurate."