The ACLU filed a public records request for all information about using stingray devices from the Sarasota PD and had an appointment to review the documentation, when the US Marshal Service went in and effectively raided the police department, taking all of the documents that the ACLU were going to view.
Something similar happened in Tallahassee after it was revealed that said department had used stingrays 200 times without telling a judge. The stingray manufacturer had made the police department sign non-disclosure agreements and the department thought that precluded telling judges. Interesting how corporations can now dictate law enforcement behavior.
A stingray is a piece of surveillance equipment that mimics a cell tower. It broadcasts a stronger signal than a tower which forces all of the cell phones in the area to link to it. By moving the tower around, you can triangulate and more accurately locate the phone with a specific number than is possible with tower information alone. The kerfuffle revolves around the detective getting a 'trap and trace' warrant which is effectively a phone tap, for deploying this stingray, rather than a probable cause warrant that is normally used with them.
http://www.wired.com/2014/06/feds-seize-stingray-documents/