One great thing about social networking sites like Facebook is that you can tightly curate your online persona, emphasizing whatever details you feel best (or most flatteringly) describe you. And, with finely controlled privacy settings, you can decide what information to keep offline. But what if your omissions make a big, unintentional statement about who you are? Technosailor's Aaron Brazell examines "privacy implications based on omission" on sites like Facebook and finds that the information we choose to exclude may not be so secret.

Brazell writes about a recent report from MIT on how we reveal information without meaning to. "The study was called Project Gaydar and reported a high degree of accuracy in identifying the sexual orientation of people who explicitly did not share that on Facebook." So even people who were able to navigate Facebook's often complex privacy setting to keep their orientation offline were, in a sense, sharing it with the world without ever meaning to.

Brazell lists several other possible ways we reveal things without meaning to. "For instance, is it logical to deduce that when a person's tone online moves from gregarious to tame, they may be job hunting and wanting to put their best foot forward? Or maybe in the early stages of a new, burgeoning relationship? What can be surmised by a spate of new LinkedIn recommendations? Is a pattern of Twitter status update frequency something that can be reasonably used to deduce some meaning?" The possibilities are endless and all it takes for this information to get out is a little deductive work.

Alarmed? Curious? Not sure how to deal with this ambiguous privacy threat? "My friend, and data monkey, Keith Casey and I are proposing a panel to explore this more at SXSW," writes Brazell. "We would love your vote to ensure we get selected. It's a fun topic and one that is front and center in an age with increasing privacy concerns." Well there you go.