Dave de Vos
I think forum members should avoid insulting other forum members.
The hard part is that what one person perceives as honesty and humour, is perceived as an insult by another. And what one person perceives as respectful, is perceived as hypocrisy by another. This perception depends on personal and cultural attributes of a person.
The best way I've found to deal with people both online and in real life, is to only react to what I perceive as an insult if it's directed to me. And the most effective reaction so far seem to be to just say "I think that's insulting.". Usually if the other person didn't actually mean to be insulting, they tell me so, and all's well again. If they did in fact mean to be insulting, well, now they know that they succeeded and I know that they're a person I don't want to waste my time on.
If the remark wasn't actually directed at me, I wouldn't be surprised to get a response of "what's it to you" or something along those lines. So I leave it to other people to respond to insults that are directed at them.
In my experience trying to teach other people or somehow influence how they behave online is futile. I wish people would just stop doing it, but of course I can't make anyone do that either.