Good example.
If he was alive and you posted it on our website and he sued us in Ontario court, we'd be toast.
First of all, it would be considered defamatory right off the bat.
We would not be able to use the defence of "truth" because, in order to do that, we would need witnesses to come into the court and give first-hand testimony that they saw him molest a child or they were molested by him as a child and that they saw him participating in a "totalitarian death cult". They'd also have to define a "totalitarian death cult" and prove that Islam is one (with first-hand testimony).
If we were to make the argument that the above statement was fair comment, we would have to show that it was based on facts and that you honestly believed what you wrote.
However, since you didn't lay out all of the facts that you based those opinions on in the post(s) in which it appeared, we would not be allowed to speculate as to what facts you were relying on. We would also not be allowed to say whether or not it was your honest belief, because that would be "opinion evidence" and, therefore, not admissable. So, the fair comment defence would fail.
Even if we had court transcripts that clearly showed that the plaintiff had done those things, or reams of news articles, videos, or history books, none of that would be admissable because they are all considered "hearsay".
In short, if you are a forum administrator in Canada and someone posts a negative comment about someone on your site, you are completely liable and you have no defence.
If you appeared in court and said what facts you based that statement on and that it was your honest opinion, you might have a chance of being allowed the "fair comment" defence, but, in our case, they simply found over and over again that "no person could honestly hold that opinion".
Game over.
Thankfully, in America we are (so far, largely) Free to our opinions and to express them without threat of lawsuit.
Come on down! What with Global Cooling, you might find the political and actual climate more appealing!
You would think all major websites that allow commentary by posters could be shut down this way.
Are any websites in Canada allowing these type of posts?