I don't care for Captchas because some of the numbers/letters are illegible and I take too much time looking at the next set. Doing the image ones where you check off the boxes of whatever takes forever and sometimes it makes me do it all over again and that's frustrating. I don't have a better option than Captchas though because our spammers get through anyway even though they aren't always bots.
I've used reCAPTCHA until recently, but got put off from doing so from another forum due to concerns about the amount of data transferred to Google:
- The website where the CAPTCHA is integrated
- User agent of the browser
- IP address of the port
- Screen and window resolution
- Language set in the browser
- Time zone
- Installed browser plugins
- It is checked whether a Google cookie has been stored in the browser - if not: a cookie is created
As a result, I reverted to using http://textcaptcha.com/ which generates random questions for the end user to answer.
I haven't failed. I've just found 10,000 ways that won't work.