What is privacy? Some define it as the right to decide which of your information is to be made public and to what extent. When I talk about privacy, I have in mind this definition.
I decided to keep away from Facebook about two years ago. Several incidents happened that have made me sick of that social networking service. Most of them was about privacy. If I wrote about the incidents, I would inevitably invade the privacy of those concerned. So, I cannot do so. But this I can say: they convinced me that when involved in Facebook you can never protect your information from being made public without your consent. Surely, you can prevent tagging. But your information can be published without you tagged on it. So you can never protect your privacy. Therefore, when I say that I keep away from Facebook, it means that I try to keep distance not only from it on the Internet, but also from those who feel no hesitation about posting others' information.