Usenet

Usenet is also called network news, NNTP, or just news. It can be likened to a distributed bulletin board, where messages posted on one board (or server) are forwarded to other boards (or servers) in a network. There are many specialized newsgroups and news servers. An ISP will often provide a news server for its customers, and large corporations occasionally provide them for use by staff. Commercial Usenet providers are in operation, and an archive of Usenet posts is available at http://groups.google.com/.

The first spammers collected their email addresses from Usenet. Even today, it is the second greatest source of email addresses.

Most news servers do not require a user to provide an email address to read posts on newsgroups. However, most require a user to provide an email address when posting messages. If a user only reads newsgroups, their email address will not be collected by spammers from Usenet. Some mailing lists are also echoed to Usenet and subscribers to it are at risk.

Using a technique similar to that of a the web spider, spammers collect email addresses using programs that download many Usenet posts and scan them for email addresses. This approach has been in use for many years. As a result of collection of email addresses by spammers, a number of common techniques have come into use to prevent email addresses from being harvested.

Users can manually obfuscate their email addresses in various ways. For example, instead of using the symbols '@' and '.', the words 'at' and 'dot' are substituted. So, user@domain.com becomes user at domain dot com. Regular Usenet users recognize this obfuscation and will be able to decipher it easily.