Kate,
 
When one posts a message to multiple usenet newsgroups and publicly
accessble newsgroups, that individual has "spammed" the net. Technically,
to be a true spammer, you need to cross post to the whole usenet and
listserv community (well over 6,000 groups). Perhaps the most famous
example is the "make money fast" internet chain letters: a money making
pyramid scheme that is based on spamming as many news groups as possible.
 
Recently, the traditional definition of "spam" is less applied and the term
primarily refers now to unwanted "junk mail" advertising. The majority of
this traffic is from the "red light" (or more appropriately, black page)
sector of the internet. A great deal of spamming comes from
hardware/software sales and promotions also.
 
Spam is more than just harmless junk mail. Just as a mass snail-mailing is
wasteful of resources (paper, postal workers), spamming can cost the
internet thousands of dollars in bandwith and processing time. These hidden
costs may not be apparent to the average net-head now, but if spamming
continues to grow unchecked, we all will bear the burden.
 
For more information on spam, and the internet itself, check out Patrick
Crispen's Internet Roadmap, available on many servers (not spam, but
satellites). I like MIT's at
 
http://www.its.rmit.edu.au/publications/Roadmap/welcome.html
 
Welcome to the ether,
 
David Johnson
 
"Forget world peace, try visualizing turn signals."