Back in August 2012, we reported on how the American Civil Liberties Union was compelling the FBI to fully disclose how it interprets the results of the United States v. Jones case—a unanimous Supreme Court decision establishing that law enforcement does not have the authority to put a warrantless GPS tracker on a suspect’s car.

As we reported then, other types of high-tech surveillance and monitoring by law enforcement continue on a nearly daily basis around the country. Cops are using everything from tap and trace, ping data, license plate surveillance, and other techniques as a way to keep tabs on suspects and innocent citizens without going through the threshold of a judicially reviewed probable-cause-driven warrant.

Now, the ACLU has received a response to its query—with nothing. The FBI sent the ACLU back pages (PDF) upon pages (PDF) that are heavily redacted, providing zero insight into what this policy actually is.

Can the Feds track your boat?

The ACLU first caught wind of the two FBI memos in question after hearing FBI General Counsel Andrew Weissmann speak at a legal conference in San Francisco in February 2012.

In a 12-minute video posted online, Weissmann spoke about two memos: one focused on the use of GPS tracking on forms of transportation beyond cars, the other regarding how Jones applies to tracking methods outside of GPS (presumably like cellphone ping data).

“Is it going to apply to boats, is it going to apply to airplanes?” Weissmann asks in the video. “Is it going to apply at the border? What’s it mean for the consent that’s given by an owner? What does it mean if consent is given by a possessor? And this is all about GPS, by the way, without getting into other types of techniques.”

And those questions remain wholly unanswered.

“The Justice Department’s unfortunate decision leaves Americans with no clear understanding of when we will be subjected to tracking—possibly for months at a time—or whether the government will first get a warrant,” Catherine Crump, an ACLU staff attorney, wrote on Wednesday.

“This is yet another example of secret surveillance policies—like the Justice Department’s secret opinions about the Patriot Act’s Section 215—that simply should not exist in a democratic society. Privacy law needs to keep up with technology, but how can that happen if the government won’t even tell us what its policies are?”

Needless to say, the ACLU says its fight isn’t over, and it will move this further up the legal chain.