Technological advancements allowing the tracking and storage of mass amounts of information have sparked legal controversy in recent years. The US Supreme Court [official website] ruled [JURIST report] in January that the government's attachment of a global positioning system (GPS) device to a vehicle, and its use of that device to monitor the vehicle's movements, constitutes a search under the Fourth Amendment [text]. Last August the ACLU announced that their affiliates were sending approximately 375 requests for information in 31 states to reveal how law enforcement uses location data tracking on cell phones [JURIST report]. Smartphones now come with built-in global positioning systems (GPS), allowing users' movements to be tracked by law enforcement agencies, sometimes prior to having the phone in custody. In January 2011 the Supreme Court of California ruled that law enforcement officers can legally search text messages [JURIST report] on a suspect's cell phone without a warrant incident to a lawful custodial arrest. The California decision represents a split from the US Court of Appeals for the Third Circuit 2010 ruling and a 2009 decision [JURST reports] by the Ohio Supreme Court holding that police must obtain a warrant before searching data stored on a cell phone.