Just wanted to add my thoughts on this topic. I agree that there are some posts and comments that to me are offensive based on the my culture and the way we were raised as children (like talking freely and openly about sex and other topics, in our culture we always use methapors). I even PMed once to Qatari regarding a thread that went really nasty with name calling and revealing of people's names.
Then I thought hey this is the internet and these are people with different opinions, way of thinking, inhibitions, culture and sensibilities. The reason the internet was created was to have a free exchange of ideas without government or religious censorship. So what maybe offensive to me (except matters of basic human decency and morality - like that rape comment) may be just ok to other cultures. So it's up for me to accept it or just ignore it. It is sometimes in these exchanges heated or not, nasty or comical, that we broaden our knowledge of other cultures and each others sensibilities. And with the experience we all grow. As the saying goes: whatever does not kill us only makes us stronger. Well, that's just my two cents worth.