PatCavit.com

This is a pretty serious problem, and currently CAPTCHAs are used on a lot of sites. I know I’m not alone in really hating most CAPTCHAs: they’re hard to understand, it’s an annoying step to have to take, and I never know whether to enter it in upper or lower case. Nothing I run has had any spammer issues, mostly due to a lack of anything interesting for spammers on my sites.

If I had to try and prove signups were from people though, I’d be damn tempted to use Microsoft Research’s recently announced Asirra Project. It’s a lot like KittenAuth only they’ve got a DB of 2 million pet images and add about 10k new ones each day. Definitely an interesting approach. If cute animals aren’t your thing maybe you would prefer Hot Captcha which Asirra cites as inspiration. They went with animals for a couple of good reasons, hotness is relative and pictures could be offensive.

All interesting attempts at solving a very complex problem: how does a machine generate something that a machine cannot recognize, but a human can?