Aw, Quincy. I wanted HiFi to provide his "evidence" of wrongdoing.
IF HiFi ran a business and there was a manipulation of business review comments by Yahoo that swayed consumer opinion of the company, that conceivably could be a legal problem for Yahoo. It has been a problem for other review sites. But as described by HiFi here, there is nothing wrong with Yahoo or any of its forums, or any forum, editing content, even if to do so slants the content right or left.
You and I both know this. I was trying to provide a teaching moment for HiFi, to learn it for himself. Since he clearly doesn't believe anything we tell him.
(I am in the process of reviewing his post hx and that is becoming quite clear. I'm not sure why he even bothers to come back since he doesn't accept anything we tell him.)