The Department of Justice issued new guidelines on Thursday reining in the use of confidential cellphone surveillance technology, and suggested they would enhance privacy rights.

Under the new policy, Justice will need to “obtain a search warrant supported by probable cause before using a cell-site simulator,” technology that is also known as a “Stingray.” However, “limited exceptions” will still be available for agents in “exigent circumstances.” The data that the program collects on innocent people must also be deleted at least once each day.