Jonathan Wilkins of iSEC Partners said the method had a total success rate of 17.5 percent against reCAPTCHA. The rate is significant because of the wide use of botnets by spammers and other miscreants. Even a modest-sized network of 10,000 infected machines with a success rate of 0.01 percent would yield 10 successes every second. That could translate into 864,000 new accounts every day, he said.

...

A Google spokesman said the data collected in the report was collected in early 2008 and didn't reflect enhancements made to reCAPTCHA since then.