In the last two months, several Internet security firms have suggested that spammers had devised a way to bust the “captcha” that is protecting Gmail. This would allow them to use the popular e-mail service to drown the rest of the Internet with e-mails containing links to malware and clumsy Viagra propositions.

Captchas, which I wrote about last year, are the popular but pesky tests designed to distinguish software bots from us thinking, letter-recognizing humans. If hackers had indeed added the Gmail captcha to their trophy case, which already includes captchas protecting Hotmail and Yahoo Mail, than little stands between the spammers and the rest of the Internet. Breaking Google Captchas for a Day - Bits - Technology - New York Times Blog