[rarestnews]

Also it's sometimes used as porn-bait (i.e. enter captcha to enter the "free" site).

Human solving is pretty cheap too. I've heard quotes about $2 for 1000 captchas. I guess with 1 click instead of 5-7 letters + enter - it's going to be cents per thousand soon enough, cause you don't even need to know keyboard well or type fast enough. So, I'd say that might be a step backwards.

[DenisM]

I've heard this pron meme before, but didn't see any actual proof. Do you have sources?

[rarestnews]

You can't be that lazy :)

http://google.com/search?q=porn+captcha http://news.bbc.co.uk/2/hi/technology/7067962.stm http://www.concurringopinions.com/archives/2007/10/creative_... (note the quoted part from article) and probably a thousand others

Also I personally did stumble to Google's captcha in quite a few sites (borderline porn) posing it as their own for registration purposes (sometimes monochromed though). Google has easily recognizable captcha.

[DenisM]

A few years back (probably in 2006 or 2007) I talked to a bunch of researches who were working on image recongition and they told me they searched high and low for any proof of this and didn't find it. So I have had a cached opinion since then until about 5 minutes ago. :-)