I use Facebook at least once a day to keep up with relatives, friends, colleagues, colleagues of colleagues, and interest groups. In many situations, I find that Facebook is much more efficient than relying on e-mail, Twitter, and RSS feeds. Sad to say, the frequent use of Facebook without regularly inspecting and modifying privacy settings (and other settings) will result in exposing parts of your life to the world, seeming without your informed consent.
One person I rely on for good advice regarding privacy issues and social networking sites is Jeff Elder. His recent blog post, "Walk through Facebook privacy settings" is something I recommend members of Facebook read read and follow. It might take up to 30 minutes of your time, but the time you spend will be important.
Through blogging, so much of "me" is out there, and this is the case for many others. Even so, it is important for me to have control over what Jeff Elder calls "the giant peephole". What people can see through the peephole of Facebook changes, often in the periphery of our awareness, and as a result, we might be sharing more information to others, including marketers, than we would like.
(Jeff Elder is a longtime Charlotte Observer columnist who studied social media on a Knight fellowship at Stanford University, blogs about social media and networking for folks in the Charlotte, NC region.)