In a major victory for journalists and privacy and transparency advocates, a federal court has started the process of unsealing secret records related to the government's use of electronic surveillance.

US District Court Judge Beryl Howell said at a hearing Friday morning that absent an objection by government attorneys, the court would post to its website next week a list of all case numbers from 2012 in which federal prosecutors in Washington, DC applied for an order to install a pen register or a trap and trace device.

A pen register is an electronic apparatus that tracks phone numbers called from a specific telephone line (though the 2001 USA PATRIOT Act expanded the definition of pen register to allow for collection of email headers as well). A trap and trace device is similar, but tracks the phone numbers of incoming calls.

For decades, court records relating to these documents have typically been sealed in their entirety, including even the docket numbers. Next week's release, which is in response to a three-year-old petition filed by VICE News, will be a crucial first step in learning details about the electronic surveillance orders, and the beginning of a multilayered process that will ultimately lead to the disclosure of thousands of pen register applications dating back at least five years.

Pen registers and other similar devices do not intercept the content of communications, and the government is not required to obtain a warrant or to have probable cause that the target committed a crime. Instead, a government attorney can simply obtain authorization by filing an application with a federal court stating that the information that would be obtained is "relevant" to a criminal investigation. The FBI, Drug Enforcement Administration, Department of Homeland Security, and other federal law enforcement agencies have used pen registers.

'We have a right to know how often the government uses powerful surveillance techniques such as pen registers.'

In August 2013, we filed in US District Court for the District of Columbia asking the court to publicly release "all applications, supporting affidavits, and court orders regarding pen registers, trap and trace devices, tracking devices, cell site location, stored email, telephone logs, and customer account records from electronic service providers, except for those which relate to an ongoing investigation." Additionally, we petitioned the court to change the protocol for sealing and nondisclosure related to future pen register applications and other electronic surveillance orders.

The legal proceeding is somewhat unusual in that we did not seek the release of documents related to a particular case, but instead asked the court to unseal records en masse. This approach was necessary, said Jeffrey Light, a Washington, DC–based attorney who is representing VICE News in the case, because of the multiple layers of secrecy that surround pen registers.

At Friday's hearing, Howell approved a plan that would lay the groundwork for the systematic review and unsealing of a large volume of federal court documents related to the government's use of electronic surveillance.

Orders authorizing the use of a pen register are initially sealed to prevent tipping off the subject of the investigation that their communications are being monitored. However, courts rarely reexamine the need for continued secrecy after the investigation is closed. As a result, virtually all pen register applications and orders have remained hidden from public view years or even decades after the investigation has ended.

Privacy advocates have long expressed numerous concerns over the potential for abuse in the government's use of pen registers.

"Pen register orders have been used over the years for surveillance that's much more intrusive than one might imagine at first glance: from real-time location tracking, to concealing the operation of cell site simulators (Stingrays), to purportedly authorizing the NSA's bulk collection of all Americans' telephone metadata," Nate Cardozo, a senior staff attorney at the Electronic Frontier Foundation, told VICE News.

He added, "When surveillance tools are authorized in secret, public oversight becomes impossible, especially in cases where the pen register evidence is never introduced in a criminal prosecution. We have a right to know how often the government uses powerful surveillance techniques such as pen registers, and there's no reason why the government should keep that information secret even years after the underlying investigations have closed."

It's not just privacy advocates, however, who have an interest in seeing pen register orders unsealed. Katie Townsend, an attorney for the Reporters Committee for the Freedom of the Press, which joined our case last month in an effort to "assert the broader interests of the press and the public," told VICE News it's difficult for the media to report on certain aspects of the government's use of electronic surveillance because of the intense secrecy surrounding the issue.

Townsend said Howell's decision is "an important first step toward greater transparency on this issue."