In a newly released report, security researcher claims that Google’s
reCAPTCHA, one of the most widely adopted free CAPTCHA services, contains
weaknesses that would allow a 10,000 infected hosts botnet the ability to
achieve 10 recognition successes every second, allowing it to register 864,000
new accounts per day.
In response, a Google spokesman stated that the report relies on data
collected in early 2008, and doesn’t take into consideration the effectiveness
of the current technology used against machine solvers.