personal attacks & ad-hominem arguments
Olivia's work and public activites are something that most fans care about. This board is there to discuss that and we all have an interest in keeping the discussion lively and inclusive. You can disagree in a productive way the principle is simple -
Discuss the topic - not the person posting the topic!
Don't descend to the sort of argument "That's a load of rubbish because you are a jerk/stupid/someone I hate/member of some group I don't like/whatever". If you do that you have just shown you were unable to find anything to say about the other person's point of view. That is not discussion. Ad-hominem arguments are all too common on the Net where some people try and devalue someones argument by attacking the the person. They add heat, not light to any discussion and aren't welcome on this board.
(ad-hominem - from the Latin against the person)