Using tarpits to trap spammers
A tarpit slows down spam by reducing the effectiveness of the spammer’s weapons.
Many email addresses appear on the web, and spammers employ harvester applications to collect those addresses for future mailings. Some victims fight back with a tool called a tarpit. A tarpit is an automatically-generated website that baits a harvester with a complex tangle of meaningless URLs. The longer you can pull the wool over the harvester’s eyes, the longer the list of tarpitted addresses will become. Under ideal circumstances, the harvester would end up with a list full of tarpitted links. To allow this to happen, the bait site must publish more links to itself than an average website. I ran a mini spider I developed myself against 23,000 pages and determined that each page had an average of 6.4 new links. The typical tarpit may publish 20 new links per page - three times the average value. Every round adds to the number of tarpitted links in the harvester’s list of sites.