Knowspam.net: Tired of Spam Yet?
I just knew Knowspam.net’s (an anti-spam service) challenge-response spam system (a new sender is sent an email with a link to a captcha page to prove they’re not a spammer script) had to have some strange side effects.
I experienced one today, subscribing to Evolt’s the List. After entering my email in their standard Mailman form, I was sent a confirmation email. Knowspam automatically replied with an email requesting them to visit a webpage. EZMLM interpreted this as a confirmation and subscribed me.
The net result is that anyone can subscribe me to any similar mailing list system, since Knowspam will automatically reply to unknown senders. Well, no system is perfect.