"I'm surprised this is still news to anyone—we've been discussing it on the forums for five years."
I don't know if you're still reading this, but if you are, I'd like to share what I've learned from hard won experience, if only to keep you from making some of the same mistakes I did, once. Having dealt with trolls and other undesirables many times before, I've learned a few simple truths, worth remembering.
From the moment that your opposition shows that it holds the truth in no regard, one needs to accept that the time for a dialog is over. There is a game that you will see them play, very often, when their position is indefensible - deny everything, and drag it out. They'll deny that you said what you said or they said, even when your words and theirs are still in plain sight, for all to see. They'll try to manufacture their own reality. They'll then try to keep the conversation going for so long, that the story of it will become so long or convoluted that practically nobody will want to make sense of it all, allowing what would have been obvious, baldfaced lies to be overlooked, still baldfaced lies, but lies that will be accepted as having maybe been true, because at that point, in practical terms, the discussion breaks down to your word vs. the trolls. You know that you're being honest, but a total stranger, in his exhaustion, will have nothing to go on but the majority view, and the trolls network. They'll bring friends who are just as psychopathic or even sociopathic as they are. All you can do is walk off, and be done with such people, forever.
Your mistake, and it is an easy one to make, was to engage the trolls on their own turf - in forum that, if it is moderated at all, is moderated with dishonest intent. The trolls, in practice, own such forums in the long run. A far more effective, less time consuming and far less frustrating approach is to create a webpage, or write blog posts telling and, as far as possible, documenting the truth through links to outside sources. You're writing something displeasing to the company owning one of the major search engines, so you'll want to optimize your pages or posts for the primary competitor - Bing.
The trolls will try to lure you back onto their own turf, by playing the game of pretending that the argument is won by whoever speaks last. Remember that you're not the only person on the planet who know that's nonsense, and ignore them. You'll end up spending a lot less than five years dealing with somebody else's bad behavior, and the trolls will end up talking to the only audience they ever deserved to have - themselves.