This is a highly concerning allegation, and it does explain some interesting results I've noticed lately. I've wondered why, especially when searching for products, an expected result isn't there unless I invoke it by name. I'd chalked it up to their competition having more mindshare and thus a higher page rank score. Now I'm not so sure.
Worse, it somewhat supports claims that the far-right has been making, although those claims still completely miss the mark.