Are we crossing a line?

Today in my CIS class, we had to discuss the use of cookies on Internet websites. According to the textbook Computers are your Future, by Bill Daley, cookies are small files written on your computer's hard disk by some of the various Web sites you visit. The original purpose of using cookies was to provide convenience to users, by temporarily storing information that was put on the website, to use for future reference. An example would be when shopping online, cookies allow shoppers to place items in the shopping basket - the cookies remember the items you browsed and saved, for easy retrieval later. The problem is though, certain marketing companies are capitalizing on this, and using information gained by cookies to advertise specific products to users, based on Web sites that were previously visited. Although this isn't directly a problem of public relations, pr, marketing and advertising are all very similar, and each have a specific audience that they are targeting. Do we go to extreme measures, even to the point of invading the privacy of others, to fully understand our target audience? Public relations does need information about their audience, however pr, marketing and advertising can obtain this information in more ethical ways - and with the consent of their target audience - than by looking at what Web sites Internet users browse.