conroy - 7:31 pm on Feb 12, 2013 (gmt 0)
I saw an early implementation of this earlier last year. I got an unnatural links notice and when I filed a reconsideration, Google got back to me with examples of 3 links that they considered unnatural. The site is quite good so I can see why they did it for me.
Removing those links never got me any increased traffic though even though I did actually get the unnatural links penalty entirely removed.