If I were a dominant search engine and there were an up and commer who was a threat to my dominance, I'd try to find a polarizing issue about them and get people talking about it and sharing it on social media. Controversies spread like wildfire! It's an easy win.
I'd also be careful to make sure none of it was tied to me and if that were even in jeopardy, I'd cut off the "partner" who was supposedly doing this behind my back.
It's also important that it come from actual humans who are forming their own opinion... you know, based on the things that they're being pointed to by vauge insinuations.
I feel like I had a real missed opportunity by not being #evil. I think I'd be pretty good at it. 😈