Using advertisements as a CAPTCHA

[pne]

Apparently, Microsoft wants to patent a method to use advertisements as CAPTCHAs (article in German).

Meaning that in order to post an anonyous comment or create an email account or whatever is now guarded by a "type the distorted letters" barrier, you might have to look at an advertisement and answer, "Name the product advertised here". Meaning that you can no longer adblock the advertisement, whether through technical means or through "banner blindness", since you'll need to read the ad in order to pass the CAPTCHA.

My first reaction was "evil", but I suppose it's not really evil per se, though annoying for a fair number of web users.