The Washington Supreme Court has ruled that police need a warrant before installing a Global Positioning System tracking device on a suspect's car. It is the first court in the country to rule this way.

"Use of GPS tracking devices is a particularly intrusive method of surveillance, making it possible to acquire an enormous amount of personal information about the citizen under circumstances where the individual is unaware that every single vehicle trip taken and the duration of every single stop may be recorded by the government," Justice Barbara Madsen wrote in the unanimous decision

She raised the prospect of citizens being tracked to "the strip club, the opera, the baseball game, the `wrong' side of town, the family planning clinic, the labor rally." The closely watched case had evoked worries about police using the satellite-tracking devices like Big Brother to watch citizens' every move.

Doug Honig, a spokesman for the American Civil Liberties Union of Washington, said ... Attaching a GPS device to a car is "the equivalent of placing an invisible police officer in a person's back seat," Honig said. "Our state constitution has very strong protections for privacy. Some other states also have very strong protections for privacy. This will be a strong precedent for them to look at and for any law enforcement agency around the country."

Our first thought: Scott Peterson, accused of murdering his pregnant wife Laci, will be very happy to hear this--although if the ruling was based on Washington's state constitution as opposed to the Fourth Amendment, it may not be adopted by California. Washington's state constitution has very strict privacy protections.