CAPTCHA module: spam control
Last modified: November 27, 2008 - 12:58
A CAPTCHA is a type of challenge-response test used in computing to determine whether the user is human. This is used in Drupal to prevent spam posts and bot activity.
Installation
- Download the module from the project page and enable the module
- Go to admin/user/captcha to enable CAPTCHA for various actions
CAPTCHA Blew IE Default Color and Font Settings
I downloaded and installed CAPTCHA ( naively ) using the SEO Checklist Module recommendations. The first time I restarted my computer afterwards, the Internet Explorer default color schemes were blown away and the system font had been replaced with something pretty awful. A bit of research made it clear that this was because I'd set up image CAPTCHA without changing the font selection from it's bitmap font default. This all took me by surprise, because it appeared to work fine before the restart. Things are mostly fixed now. I use Vista, so here are a few tips if anyone has the same problem:
Fix colors using Control Panel: You need to use Appearance and Personalization tools to get your system colors back. ( You can't recover using the Tools tab of the IE browser toolbar )
Fix system fonts: Follow the CAPTHCA true type font install instructions--install the font you want to see as a system font.
Hiccups aside, I appreciate the donation of this sophisticated and powerful module. Ditto the excellent SEO checklist module. Thank you, developers and maintainers. You do great work.
This is probably caused by something else
It is almost impossible that the Image CAPTCHA module is the cause of the symptoms described here (unless you downloaded a hacked version of the CAPTCHA module from a not trustworthy website).
The Image CAPTCHA module is just a simple Drupal module that uses the standard Drupal and PHP API's and does not interact with your operating system in way that it could change your operating system settings as you described.
Further discussion at #263013: CAPTCHA Corrupted Font Defaults for IE.
Text captcha trick
I personally hate image captchas and found that spam was getting past math captcha.
I was also getting registrations from people who seemed real, but I didn't trust - why would people in Russia and Far East be registering on a local English site with throwaway emails from spam associated freemail providers? These people had answered a simple text captcha.
So I changed things - I now ask a question that everyone who lives here knows the answer to, and if you don't, you'll need to invest a Google search in finding the answer.
So far no bots have got past it, and all the distant registrations have stopped as well. (I guess if they want be nefarious, they just want to sign up for loads of sites, and it's easier to move to the next one than try and find the answer to mine).
So, If you run a site and can think of a question that effectively filters PEOPLE, ask it with a text captcha. Try to keep the question open with as few clues as possible in the text. In the example below I'm assuming spammers might start trying "Linux" if they see "penguin".
Example - for an IT site - "What operating system has an antarctic bird logo?"
Ian Dickson
Likal.com
Image is not displayed on IE6
Hello,
I wonder if there is a restriction on IE6 that prevents images without extension to be displayed correctly.
Has anyone got this issue ?