Federal involvement in local open records proceedings is unusual. It comes at a time when President Barack Obama has said he welcomes a debate on government surveillance and called for more transparency about spying in the wake of disclosures about classified federal surveillance programs.

One well-known type of this surveillance equipment is known as a Stingray, an innovative way for law enforcement to track cellphones used by suspects and gather evidence. The equipment tricks cellphones into identifying some of their owners’ account information, like a unique subscriber number, and transmitting data to police as if it were a phone company’s tower. That allows police to obtain cellphone information without having to ask for help from service providers, such as Verizon or AT&T, and can locate a phone without the user even making a call or sending a text message.