let the kittens fight bots !

[SinbadEV]

as a captcha, it is idiotic to the extreme.
When you're down to working on individual questions yourself, you can just as well simply ask users to write "hello world" or something like that into a form field, not blocking the blind. THAT is not bot solvable at all. On your blog, chances are you'll only ever need to make one question EVER, rather than categorize hundreds animal images as to require imaginary spammer who personally hates your guts to spend same time categorizing those images.

I don't know, pissing off spammers seems like a relatively positive side effect.

[dizekat]

as a captcha, it is idiotic to the extreme.
When you're down to working on individual questions yourself, you can just as well simply ask users to write "hello world" or something like that into a form field, not blocking the blind. THAT is not bot solvable at all. On your blog, chances are you'll only ever need to make one question EVER, rather than categorize hundreds animal images as to require imaginary spammer who personally hates your guts to spend same time categorizing those images.

I don't know, pissing off spammers seems like a relatively positive side effect.

microsoft did one with cats and dogs based on images from petfinder, which is going to last about as long as it takes spammers to obtain the database (images then can be hashed).

Simple defeat of captcha: make a porn site that requires to solve captcha to see porn, use it to solve captcha to spam forums with links to this porn site. If you want to also defeat it automatically you can build database of images.

[SinbadEV]

as a captcha, it is idiotic to the extreme.
When you're down to working on individual questions yourself, you can just as well simply ask users to write "hello world" or something like that into a form field, not blocking the blind. THAT is not bot solvable at all. On your blog, chances are you'll only ever need to make one question EVER, rather than categorize hundreds animal images as to require imaginary spammer who personally hates your guts to spend same time categorizing those images.

I don't know, pissing off spammers seems like a relatively positive side effect.

microsoft did one with cats and dogs based on images from petfinder, which is going to last about as long as it takes spammers to obtain the database (images then can be hashed).

Simple defeat of captcha: make a porn site that requires to solve captcha to see porn, use it to solve captcha to spam forums with links to this porn site. If you want to also defeat it automatically you can build database of images.

What if you intermingled the kitten pictures with judgmental looking nuns and grandmothers?

[dizekat]

What if you intermingled the kitten pictures with judgmental looking nuns and grandmothers?

then the captcha would be unsuitable for large fraction of the internet... unless at least the nuns are hot.