Internet Word Tests Confusing Users

You've seen them - the distorted collections of letters and numbers against odd background where you discern the characters and type them into a box so a web site knows it's dealing with a person and not a spam bot. The New York Times had an article about how the tests to fool spammers, called captchas (Completely Automated Public Turing Test to Tell Computers and Humans Apart), are starting to twist the minds of people, as well. I know that I've seen one or two where I had to try a couple of different times: Is it upper or lower case, or a 1 or l? They keep getting tougher because people develop programs to defeat them.