Google Claims Gmail Verification System Cracked by Humans

Last month, security firm Websense claimed that the Gmail CAPTCHA system had been automatically cracked by machines, resulting in a large number of spam accounts. This claim can be partially verified by the statistics released a few days ago by MessageLabs. In February 2008, the amount of spam emails sent via Gmail accounted for 2.6% of the total, doubling that of January. Of course, this does not indicate that Gmail has poor anti-spam capabilities, as the number of spam emails sent via Yahoo! Mail accounted for 88.7% of the total. With the amount of spam doubling, was Gmail's CAPTCHA system really automatically breached by machine algorithms?