Privacy concerns

Online Privacy is a major concern to most of people, who would like to feel be manipulated by other people. I am reading an online novel the advertisments they have on the novel are the web page I recently viewed. I wanted to buy a new computer, so I visited some website which sales computer product, but how those advertisments end up on the novel web page? People nowdays are looking through every possible aspect to make money. So privacy has become a less concern for those company. Anybody ever realise that when you received wrong phone call that could be a kind of infomation leak? especially when you received more than one in a day. What is the odd that out of the american population you two or more strangers call you in one day?