There are always inherent problems with any forum or on-screen communication.
Firstly, the tone of the post can be mis-interpreted by the reader: innocuous comments can be read as aggressive if the reader is in the wrong mood.
Secondly, it’s very easy for trouble-makers and stirrers to hide behind faceless avatars and keyboards: they would never make certain comments to people’s faces, but feel they can on-line.
A little consideration and, dare I say it, kindness on both sides is always the way forward.