And with millions of workers now using social networking in their professional as well as personal lives, those privacy risks extend in a very big way to the enterprise.

, which released its last week, devotes an entire section to "Facebook and your privacy." Its findings may not surprise most CISOs, but will likely be unsettling all the same.

More than 150 million Americans use the site, with that number increasing daily. And in exchange for helping people do things like stay in touch with family and friends, find old classmates, share photos, organize around interests and causes, promote their businesses and learn about the tour schedule of their favorite band, Facebook collects and distributes vast amounts of sensitive personal information. It is one very prominent example of Big Data.

notes Facebook CEO Mark Zuckerberg's that, "We do privacy access checks literally tens of billions of times each day to ensure we're enforcing that only the people you want see your content."