- From: Ben Maurer <bmaurer@andrew.cmu.edu>
- Date: Mon, 16 Jul 2007 11:08:48 -0700 (PDT)
- To: Gez Lemon <gez.lemon@gmail.com>
- cc: Al Gilman <Alfred.S.Gilman@ieee.org>, wai-xtech@w3.org, Colin McMillen <mcmillen@cs.cmu.edu>
Hey,
On Mon, 16 Jul 2007, Gez Lemon wrote:
> Hi Ben,
>
> On 16/07/07, Ben Maurer <bmaurer@andrew.cmu.edu> wrote:
> <quote>
> Well, if they disable images, they're screwed with CAPTCHAs anyways --
> they won't be able to see the images. A blind, dialup user trying to save
> bandwidth would still be able to use the CAPTCHA because they'd see the
> psudo-alt text.
> </quote>
>
> Not at all. Presumably, the CAPTCHA won't have alt text, or any robot
> would be able to answer it. People who deliberately disable all images
> can enable any image they like, providing they know it's there - so
> would choose to display the CAPTCHA image to solve it.
THe CAPTCHA will have alt text that describes what it is ("This is a
visual challenge....")
> The technique you described used CSS for a functional link ("get a new
> challenge"). If the text is moved off the screen and replaced with an
> image, someone with CSS enabled but images disabled would have no idea
> that there was text there that has been removed. You asked if there
> were any issues with that approach, and that is an issue.
Thanks for pointing out this corner case.
-b
Received on Monday, 16 July 2007 18:08:52 UTC