You might not think about the Fourth Amendment while you're using Facebook and other online tools, but you probably should.





You are no doubt familiar, now, with Facebook's concept of "frictionless sharing." You enable a social reader like the one from the Washington Post and the next time you read an article on the site, news of that textual encounter is broadcast to your Facebook friends.

It is so easy. It seems so simple. But it could also create a fundamental shift in the way that judges view people's expectations of privacy online.

That's the argument that Margot Kaminski, the executive director of Yale's Information Society Project (and sometime Atlantic contributor), makes in an intriguing new article in Wake Forest Law Review.

In Fourth Amendment cases, the Supreme Court has to determine what "a reasonable expectation of privacy" actually is. If you do have that expectation of privacy, then the government needs a warrant to look into your communications. So, if you go out in the public street and shout to the world that you committed a crime, the government does not need a warrant to use that communication. However, if you were to send a sealed letter to a friend containing the same information, you would have a reasonable expectation that the government would not be reading that note.