How hard should it be for cops to track your location? A new lawsuit revives the debate.

Privacy advocates sued a Florida police department over a controversial surveillance technology that, they say, improperly lets authorities track the movements of thousands of cellphone users without a warrant.

The suit, filed by the American Civil Liberties Union and obtained by The Washington Post, revives a perennial debate about the judicial standards law enforcement officials must meet to gather geolocation information -- and once they receive a court's permission, how much of that data they can collect and store.

It also implicates decades-old privacy legislation that was written in the age of the telephone but has been liberally interpreted to allow much greater surveillance in the Internet era, according to the law's critics.

The ACLU alleges in the suit that law enforcement officials in Sarasota (FL), acting on behalf of the US Marshals Service, obtained judicial approval to use a type of surveillance tool known as a "stingray." Used in an investigation, stingray equipment can help police identify which cellphones may be operating in an area by establishing a fake cell tower; nearby devices then automatically try to connect with the stingray device, which logs the connections for forensic analysis unbeknownst to the cellphone users.