Stanford University and Tulane University researchers crack audio captchas. Program called Decaptcha can crack 1.5% to 89% of the time. Microsoft, eBay, Yahoo and Digg sites vulnerable to automated attacks. Researchers recommend tightening up security through use of more symantic noise. They also want to analyze the ways humans make mistakes and the ways computers make it more difficult and costly to device programs that defeat them, they say. The researchers say they are working on ways to break Captchas that use entire words rather than just characters.”]