CAPTCHA Hall of Shame

by Critical Hippo

Contents

• The problem
• Inaccessible
• Confusing
• Good examples
• Links

The problem

Advertisers who lack scruples have been deploying "spam bots," or automated processes that search for guestbooks, blogs, web forums, wikis, and other web sites that publish content written by the public, and send advertising messages to them. Some administrators of guestbooks, web forums, and the like have installed a visual CAPTCHA system to prevent automated processes from sending spam. This works by generating an image containing distorted glyphs of random characters, requiring the user to read the characters out of the image and enter them into a text field, and then when processing the form, making sure that the characters match the characters used to generate the image. Unfortunately, users behind a text terminal, such as visually impaired users who use a screen reader or refreshable braille display have no way of reading the image, no way of answering correctly, and no way of sending a message. Excluding visually impaired users in this way will likely run afoul of anti-discrimination laws in several countries, such as the Rehabilitation Act in the United States or the Disability Discrimination Act in the United Kingdom. For more information, please see "Further reading" below.

Sites made completely inaccessible by CAPTCHA

These provide no way for a person with a disability to contact the administrator in order to negotiate an alternative way of proving the person's good intentions, or they make blind users' access significantly more expensive.

• area51.phpbb.com uses the same text as some of the "Good examples" below but gives an obviously invalid e-mail address:

  To prevent automated registrations the board administrator requires you to enter a confirmation code. The code is displayed in the image you should see below. If you are visually impaired or cannot otherwise read this code please contact the Board Administrator (do_not_email@nowhere.tld).

  Last checked on August 8, 2006.
• RapidShare - In order to download a file, the user must either solve a CAPTCHA or pay 10 EUR (roughly 12 USD) for a premium account.
• Ronblog - CAPTCHA image, no alt attribute, invalid HTML. I have entered discussions with ronblog. Last checked on August 8, 2006.

Confusing examples

These sites provide a way for a visually impaired person to contact an administrator, but only determined users are likely to find it.

• Wikimedia Commons links to Special:Captcha which mentions (but does not obviously link to) Commons:Contact us which links to Commons:Help desk, which permits anonymous posting. (Some other Wikimedia sites, such as English language Wiktionary, use the same CAPTCHA. The English language Wikipedia does not use a CAPTCHA at all.)
• YTMND Forums: The registration page has a CAPTCHA, and the page to contact the administrator also has a CAPTCHA! You have to use the back button several times (or retype www.ytmnd.com), scroll down to the bottom of the page, click Contact Us, and finally see a support address. Last checked on August 8, 2006: address confirmed working ☺

Good examples

These sites have recognized the inherent inaccessibility of a visual test and made an effort to present a straightforward way for inconvenienced users to contact the administrator, such as an e-mail address or a link to a web form.

• gbadev.org (e-mail link)
• Google Accounts (link to this form)
• nesdev.parodius.com (e-mail link)
• Pocket Heaven (e-mail link)
• Slashdot (e-mail address in alt attribute)
• Pluralsight Blogs ("what's this?" links to instructions) Moved from "inaccessible" on August 8, 2006.
• Bemanistyle no longer appears to uses a CAPTCHA. Moved from "confusing" on August 8, 2006.

Further reading

• Captcha - encyclopedia article from English Wikipedia
• Web Accessibility Initiative- "Strategies, guidelines, resources to make the Web accessible to people with disabilities"
• Inaccessibility of CAPTCHA - a Note from the W3C
• PWNtcha - captcha decoder
• Let's stop inaccessible CAPTCHAs - If you can see CAPTCHAs and want to help fight for those who cannot, this page has boilerplate text to use when commenting to blogs.
• WP-Gatekeeper - If your blog uses WordPress, you can randomly choose a non-image-based challenge to send to the user.
• CAPTCHA Codes are not Accessible at Pete Freitag's blog
• Reading and Subscribing to Blogs Through RSS - American Foundation for the Blind recommends using Bloglines because too many other RSS tools use a visual test. In addition, the page accuses Yahoo! of not following through its promise to telephone blind users in order to help them create accounts.
• Quiz 1.1.5: Did a CAPTCHA catch ya? at Access Matters

Opposing viewpoints

• If You Are Blind and Reading This.... - author seems to think that the World Wide Web is not designed for blind people

Contact the author

You may contact this Critical Hippo through e-mail at criticalhippo at pineight dot com