The judgment comes courtesy of Daniel Rigmaiden, a reclusive former tax fraudster-turned-government transparency advocate who first exposed the StingRay's existence after being busted by one in 2008. Initially writing appeals while imprisoned on fraud charges, Rigmaiden has worked for years sleuthing out the secretive devices, resulting in revelations of their use by dozens of agencies and police departments across the country. Rigmaiden was released on probation in 2014 after taking a plea deal.

Now the federal judge working Rigmaiden's FOIA lawsuit has ordered the FBI to release 8 additional StingRay documents, saying the information was "not properly withheld." The agency had tried to hide the documents, invoking the broadly-written Exemption 7(E), which can exclude records that might reveal "techniques and procedures" used in law enforcement investigations. The court rejected that justification, and the agency will now need to hand over the documents to Rigmaiden within 90 days.