Conduct becoming a writer

Once upon a time authors were mysterious beings, recognizable to their readers only by a black and white photograph on the inside flap of a hardback cover, or occasionally at book signings. The internet has changed all that. Most writers have websites, Facebook pages, blogs and twitter accounts; we are there to be found by anyone who is interested.

We also have the opportunity to disgrace ourselves like never before, achieving instant fame of a really, really undesirable kind (see this Guardian article on poor Jacqueline Howett).  Here are a few things I've learned about appearing on the internet...
It's not good to get into rows on forums. If things start to get heated I wander off and do some useful task like the washing up. I don't have to have the last word.About reviews - even the wrongest person from Planet Wrong is entitled to his opinion.Bear in mind that people you write about will come across your remarks.No one needs to know what your politics are, or your religion come to that. It may put them off, even if you aren't National Front and Wicca (with apologies to all witches).Being polite and helpful is a Good Thing. It's also good for your image.Moaning and grumbling are to be avoided.What would you add?