Comment Type reCAPTCHA First -- Only Then Log In (Score 1) 81
The Blogspot implementation: http://googleonlinesecurity.blogspot.com/2013/10/recaptcha-just-got-easier-but-only-if.html
In order to leave a comment on the post you have to do the following three steps. Step One: Decipher that often undecipherable StreetView street number. Step Two: 'OCR' that rarely legible text from Google Books project. Step Three: Sign-in with your Google or OpenID account.
As I see it, the first two steps are completely unnecessary torture of end users for the sole benefit of the Google shareholders.
Not to mention how far reCAPTCHA is from the Section 508, and WCAG accessibility standards. See: http://captcha.com/captcha-accessibility.html