One of the most common issues plaguing social networks is that anyone can create an account and use whatever name they wish. I say that I'm a famous celebrity, grab their image from Google Images, and begin posting updates as that individual. Now, the more famous the celebrity, the less likely you might be to believe that I am that person, but for less famous people, it's easier than you might think. And for normal people, it's an issue of potential identify theft.
Companies, too, have been at risk. In fact it's common to recommend that a business owner stake their claim on their profile on every possible social network, and there are even services set up to help you do that, just to ensure that someone else, like a competitor or disgruntled employee, doesn't take your "name" first.