Address Harvesting

From Spam Wiki

Address harvesting was the most often used way of collecting e-mail addresses till 2003. The technique is simple and easy to implement: a little program (the e-mail harvester) crawls through the web collecting all e-mail address it finds into a database which is used to send thousands (millions?) of spam to mostly valid addresses.

To defend ourselves from collecting our addresses we can replace the @ sign and the dot before the top-level domain with a small string (like [AT] and [DOT]) when publishing our address on the web.

You can fight against harvesters too by setting up honeypots and spamtraps.