CAPTCHA is the Typepad feature that requires you to copy a string of six hard-to-read characters before you can post a comment. I have to do it on this blog even though I am the author. Most people find it annoying. I know I do. We use such things to stop robots from leaving nasty spam on our sites.
Last December, I told Michael Sippey, Six Apart's top Tyepad guy that I really wish that visitors could get something simpler to prove they were human, such as a simple arithmetic problem like Josh Hallett uses. I also think they should be able to eliminate challenges to the post authors as well and finally, I'd like people who leave comments the option of being notified when someone else joins the conversation.
While Typepad is getting a lot better, it has not done any of these three burning wishes from this user's list. So today, after flunking a test to post a comment on my own site, I have disabled CAPTCHA. I'll see how it goes. Hopefully I will be able to manage the little maggots when they come with their spray paints and graffitti, but if I cannot, I'll just have to reinstate the annoying defense feature.