Sunday November 7th, 2010 informationliberation.com
Federal Judge Finds Warrantless Cell Phone Tracking Unconstitutional (ACLU.org)
In August, we blogged about a court decision from the federal court in the Eastern District of New York that held that law enforcement agents are constitutionally obligated to get a warrant based on probable cause before obtaining historical cell phone location information. And in September, we wrote about an opinion from the 3rd Circuit Court of Appeals holding that judges may order the government to get a warrant based on probable cause for historical cell phone location information. However, the 3rd Circuit also held that judges are not obligated to require probable cause, and cautioned that they should only require the government to meet this high standard on rare occasions. Now another court has joined the fray. In a detailed opinion (PDF) citing documents obtained through litigation by the ACLU and Electronic Frontier Foundation, Judge Stephen Smith of the Southern District of Texas held that “warrantless disclosure of cell site data violates the Fourth Amendment.”

A few aspects of the opinion (PDF) are worth noting:
As we have explained elsewhere, the ACLU agrees with Judge Smith that the government should be required to obtain a warrant and show probable cause before obtaining cell tracking information. As powerful new technologies enhance the ability of government agents to track our every move, it becomes all the more important that the courts hold the government to a rigorous standard before the government can access such sensitive information.