Patrick O'Neill writes: A senior Homeland Security official recently argued that Internet anonymity should outlawed in the same way that driving a car without a license plate is against the law. "When a person drives a car on a highway, he or she agrees to display a license plate," Erik Barnett, an assistant deputy director at U.S. Immigration and Customs Enforcement and attache to the European Union at the Department of Homeland Security, wrote. "The license plate's identifiers are ignored most of the time by law enforcement. Law enforcement will use the identifiers, though, to determine the driver's identity if the car is involved in a legal infraction or otherwise becomes a matter of public interest. Similarly, should not every individual be required to display a 'license plate' on the digital super-highway?"