[arch-general] The principle behind MSN & Yahoo invisible scanners?

Go to google.com and search for MSN & Yahoo invisible scanners. You'll find a big list. So what's the principle of their working? I'm thinking of writing a pidgin plugin to catch invisible buddies. -- Regards, Nilesh Govindarajan Facebook: http://www.facebook.com/nilesh.gr Twitter: http://twitter.com/nileshgr Website: http://www.itech7.com VPS Hosting: http://www.itech7.com/a/vps