|As soon as you post a message to a newsgroup
or put up a Web page with your email address in it, you become liable
to UCE merchants getting hold of your address. Don't forget that even
the demon.* newsgroups can propagate anywhere in the
world, and that sites such as http://groups.google.com
will be archiving your posts.
There are people running software to search through news
postings and Web pages for email addresses, either for their own use or to sell to others.
Also when you visit a Web site the server can capture your email address if you have
entered it in your browser. Some mailing lists are not properly secured, so the email
addresses of subscribers can be obtained.