While I'm all in favor of keeping the peace (and sorry to bring this up again), I don't think removing an entire thread of conversation about a company simply because someone said some nasty things is necessarily the way to go. We can't just delete things we don't agree with. Everyone is entitled to their opinion, even if that opinion is founded on assumptions with no proof. It's their right as a person to maintain that. It is possible to agree to disagree or to simply disagree with someone without getting emotionally involved. It's pixels on a screen, after all. That being said, I don't think abusive behavior should be tolerated and people who engage in blatant smear campaigns should be asked to cease and desist or face removal.
Just my 2 cents...take it for what it's worth, as always.