If you sometimes find yourself needing an open wireless network in order to check your email from a car, a street corner, or a park, you may have noticed that they're getting harder to find.
Stories like the one over the weekend about a bunch of police breaking down an innocent man's door because he happened to leave his network open, as well as general fears about slow networks and online privacy, are convincing many people to password-lock their WiFi routers.
The gradual disappearance of open wireless networks is a tragedy of the commons, with a confusing twist of privacy and security debate. This essay explains why the progressive locking of wireless networks is harmful — for convenience, for privacy and for efficient use of the electromagnetic spectrum....