Unnecessary aggression is far too common on the internet. Forums are full of people that seem to do naught but badmouth. These individuals are, on the whole, cowardly attention seekers. The type that heckle you in the street if you stand out for some reason, but only do so from the safety of the other side of the road, and only if flanked by at least 3 likeminded urchins.
We normal, slightly more civil folk outnumber them 100 to 1, but this counts for naught on the internet as nothing is face to face, making cowards feel brave. Here, we’re all just a name, an icon and whatever text we type, meaning that we’re only an entity if we are read. You don’t exist here without an audience. So, to tackle the vermin whose vocabulary consists of only profanities and whose posts are all insulting or derogatory; ignore them. Don’t respond. Let them waste their time. Even the most thick-headed will tire of talking to no one and will eventually either disappear or wise-up to the fact that you'll get a lot further being nice than by being a little prig.