Universal Design for Web Applications

CAPTCHA

Nearly everyone who uses the Web has run into those annoying little pictures of text that you’re supposed to read to prove that you’re a human being. They’re known as Completely Automated Public Turing Tests to Tell Computers and Humans Apart (CAPTCHAs). And they’ve been Public Enemy #1 for blind, low-vision, and dyslexic people for years.

In May 2008, Matt appeared with the creator of CAPTCHA, Luis von Ahn, on an episode of ACB Radio, a web radio show put on by the American Council of the Blind. What von Ahn had to offer to his audience was not a rousing defense of his creation but a thoughtful acknowledgment of what accessibility advocates have said all along: it’s not a cure for cancer, and its use comes at the cost of excluding an increasing number of real people from services they should be able to access. Go here to listen to the show: http://www.acbradio.org/archives/mainmenu/ml341.m3u.

In a world where people with good vision and reading ability (and really big monitors) can’t solve CAPTCHAs reliably, where black-hat hackers sell CAPTCHA crackers for spammers to create free email accounts, and where even the creator of the idea says it’s begun to outlive its usefulness, what do you think is happening? Surprisingly, in a lot of ways, it’s actually getting worse. Visual verification schemes are getting such a bad rap that Flickr has hundreds of uploads featuring hilariously unsolvable puzzles, as shown in Figures 5-3 through 5-5.

Figure 5-3. Cat CAPTCHA ...