Monday, October 10, 2005

Automatic License Plate Scanners & Wholesale Surveillance

The Boston Transportation Department is engaging in what Bruce Schneier calls "wholesale surveillance" in order to collect unpaid parking tickets. A white SUV equipped with two video cameras on top and a laptop computer running license plate scanning software drives around the city scanning plates and comparing them with the database of unpaid parking tickets. When a match is found, the BTD officers jump out and boot the offending car. Schneier's assessment of this kind of "wholsale surveillance":
Technology is fundamentally changing the nature of surveillance. Years ago, surveillance meant trench-coated detectives following people down streets. It was laborious and expensive, and was only used when there was reasonable suspicion of a crime. Modern surveillance is the policeman with a license-plate scanner, or even a remote license-plate scanner mounted on a traffic light and a policeman sitting at a computer in the station. It's the same, but it's completely different. It's wholesale surveillance.

And it disrupts the balance between the powers of the police and the rights of the people.

Like the license-plate scanners, the electronic footprints we leave everywhere can be automatically correlated with databases. The data can be stored forever, allowing police to conduct surveillance backwards in time.

The effects of wholesale surveillance on privacy and civil liberties is profound; but unfortunately, the debate often gets mischaracterized as a question about how much privacy we need to give up in order to be secure. This is wrong. It's obvious that we are all safer when the police can use all techniques at their disposal. What we need are corresponding mechanisms to prevent abuse, and that don't place an unreasonable burden on the innocent.

Throughout our nation's history, we have maintained a balance between the necessary interests of police and the civil rights of the people. The license plate itself is such a balance. Imagine the debate from the early 1900s: The police proposed affixing a plaque to every car with the car owner's name, so they could better track cars used in crimes. Civil libertarians objected because that would reduce the privacy of every car owner. So a compromise was reached: a random string of letter and numbers that the police could use to determine the car owner. By deliberately designing a more cumbersome system, the needs of law enforcement and the public's right to privacy were balanced.

The search warrant process, as prescribed in the Fourth Amendment, is another balancing method. So is the minimization requirement for telephone eavesdropping: the police must stop listening to a phone line if the suspect under investigation is not talking.

For license-plate scanners, one obvious protection is to require the police to erase data collected on innocent car owners immediately, and not save it. The police have no legitimate need to collect data on everyone's driving habits. Another is to allow car owners access to the information about them used in these automated searches, and to allow them to challenge inaccuracies.

Technorati tag: