A Supreme Court decision has caused a "sea change" in law enforcement, prompting the FBI to turn off nearly 3,000 Global Positioning System (GPS) devices used to track suspects, according to the agency's general counsel.

When the decision-U.S. v. Jones-was released at the end of January, agents were ordered to stop using GPS devices immediately and told to await guidance on retrieving the devices, FBI general counsel Andrew Weissmann said in a recent talk at a University of San Francisco conference. Weissmann said the court's ruling lacked clarity and the agency needs new guidance or it risks having cases overturned.