EFF takes a look at some of the surface privacy issues of Facebooks news search agenda.
The Creepy Details of Facebook's New Graph Search - EFF
There's a difference between putting information out there for anyone to find and putting information out there to be searched and sorted. If you walk down a crowded public street, you are probably seen by dozens of people—but it would still feel creepy for anyone to be able to look up a list of every road you've walked down. This is why Google Street View, for example, disguises the identity of people photographed on public streets, even though the information was not private or secret.
The Creepy Details of Facebook's New Graph Search - EFF