An interesting story from The Register (UK) about how some anti-spammers are infiltrating spammer boards for intelligence:
Spam fighters infiltrate spam clubs By John Leyden Published Friday 14th May 2004 15:10 GMT Spam fighters are gaining vital clues in the battle to keep in-boxes clean of junk mail by infiltrating spammer clubs. Online spammer forums like the Pro Bulk Club the Bulk Club and bulkmails.org have been gatecrashed by activists from organisations like Spamhaus. Steve Linford of Spamhaus said spammers know this already but they don't know who amongst their number is working for the other side. In theory the members-only forums of these sites is accessible only by invitation and only to individuals who have a proven track record in spamming. Apart from playing with the paranoia of spammers, the undercover investigation cast light on the latest spammer techniques. http://www.theregister.co.uk/2004/05/14/spam_club/