How rel=nofollow Works
The cited Danny Sullivan article has a little of his interview with Eric Schmidt:sullivan> I countered that Google seemed to have all the permission it needed, in that they’re not blocked from crawling pages.schmidt>“That’s your opinion,” Schmidt said, then joked: “If you could arrange a letter from Facebook and Twitter to us, that would be helpful.”sullivan> I pushed back that both have effectively given those letters since their robots.txt files — a method of blocking search engines — weren’t telling Google to go away.Well, why stop there?  Why shouldn't Google ignore the robots.txt file in its search for shareable nuggets for its search results, which they are equally not "blocked" from using?  The answer for both rel=nofollow and robots.txt is that Google has explicitly promised webmasters that it will not do this.  Sullivan knows this: this is bad journalism.  I'd be curious to see more of the transcript of the interview.