While I hate the objective, one has to admire the elegance and utter irony of this hack:
That's a big concern for Web portals such as Yahoo and Hotmail that offer free e-mail accounts. Software programs that automatically fill out registration forms can rapidly obtain thousands of e-mail addresses that can be used for sending spam e-mail. Telling the difference between legitimate human visitors and these software robots is a critical need.
The CAPTCHA tests are simple for humans to pass, but hard for computers. A typical test features a word with fuzzy or distorted letters, or words overlapping each other, or a word superimposed on a complex background; visitors to the site are asked to type a word they see. Yahoo began using the CAPTCHAs on its Web registration form several years ago; other Web sites quickly copied the idea.
But at least one potential spammer managed to crack the CAPTCHA test. Someone designed a software robot that would fill out a registration form and, when confronted with a CAPTCHA test, would post it on a free porn site. Visitors to the porn site would be asked to complete the test before they could view more pornography, and the software robot would use their answer to complete the e-mail registration.
The article offers more constructive utilizations of the basic of idea here, namely to trade some brain cycles on easy-for-humans-but-hard-for-computers for some small reward in a vastly distributed way.
Posted by seefeld at March 21, 2004 13:14in a spam panel, simson garfinkel asserted that some spammers outsource CAPTCHAs to low wage countries. which strikes me as one of the most ironic consequences of arbitrage :)
Posted by: Gregor J. Rothfuss at March 21, 2004 02:03 PM