So while body-cam footage is “very clearly a public interest record,” says Emily Shaw, the national policy manager at the Sunlight Foundation, it is also “just full of private information.”

What’s more, there’s no easy way to fix this. Normally, private information would be redacted out of public records. (The Sunlight Foundation recommends certain easy ways to do this for other kinds of records, such as putting all personal information-containing columns off to one side of a spreadsheet.) But there’s no simple way to compartmentalize the sensitive aspects of video footage. Video isn’t text: It’s dozens of frames per second, each its own potentially private visual. Redacting personal information out of the frame remains both expensive and unreliable, and it might not be possible with algorithms.

“If you just put a swirl blur on somebody’s face, it’s not very difficult to unswirl that blur, and then all of a sudden it’s un-redacted,” Shaw said.

The only effective redaction process might be for technicians to go through a video frame by frame—an exceptionally costly process. What’s more, even that might not be enough. “If you have additional data, then you can re-identify people who’ve been anonymized or intentionally anonymized,” Shaw said.