Exploring: reCAPTCHA: A new way to fight spam
This particular piece of news has been floating around lately. It's a CAPTCHA service that also uses the CAPTCHA information entered by users to teach computers how to digitize books.
It's so freakin' obvious, I slapped myself on the forehead. I even advocated and watched Luis Von Ahn's videos on human computation, and didn't think about it. Anyway, it seems a little bit odd, though, using a technique that computers can't solve to teach computers how to read--hence solve CAPTCHAs. Not knowing enough details--I wonder if the success of reCAPTCHA will call for the demise of the CAPTCHA.
The usual concerns of cheating were rampant on reddit comments. "What if people just put in random stuff? Then you'll have a computer that spew out crap when digitizing books." If his lecture on the ESP game was any indication, he has a number of ways to fight it (not to mention he specializes in online cheating also). In the ESP game, he counteracts cheating by giving the player a couple ones he knows the answers to and sees how much they're off. Also, he keeps track of the statistics for each image as well as throwing away results randomly. It's a little hard to see how he'll track individual users--other than through their IP--but otherwise, one can feasibly use the same methods for reCAPTCHA.