Which I found pretty interesting, in the sense that I assume that this is one of the new ways Google is going to attempt to get rid of 'spammy' websites. I would assume that on some level this is the 'Google -1', letting google know that a website contains poor content and people don't want to be seeing it (as such overtime it would be down-ranked).
I don't operate a website where I feel this type of thing would happen but, I guess this can maybe spell out a warning for black-hat SEO possibly?
Anyhow I just thought I would mention it, it's the first time I've come across this.
Thoughts Everyone ?