“You can record all you want. I just know it can’t be posted to YouTube,” said an Alameda County sheriff’s deputy to an activist. “I am playing my music so that you can’t post on YouTube.” The tactic didn’t work—the video of his statement can in fact, as of this writing, be viewed on YouTube. But it’s still a shocking attempt to thwart activists’ First Amendment right to record the police—and a practical demonstration that cops understand what too many policymakers do not: copyright can offer an easy way to shut down lawful expression.

This isn’t the first time this year this has happened. It’s not even the first time in California this year. Filming police is an invaluable tool, for basically anyone interacting with them. It can provide accountability and evidence of what occurred outside of what an officer says occurred. Given this country’s longstanding tendency to believe police officers’ word over almost anyone else’s, video of an interaction can go a long way to getting to the truth.

Very often, police officers would prefer not to be recorded, but there’s not much they can do about that legally, given strong First Amendment protections for the right to record.  But some officers are trying to get around this reality by making it harder to share recordings on many video platforms: they play music so that copyright filters will flag the video as potentially infringing. Copyright allows these cops to brute force their way past the First Amendment.

Large rightsholders—the major studios and record labels—and their lobbyists have done a very good job of divorcing copyright from debates about speech. The debate over the merits of the Digital Millennium Copyright Act (DMCA) is cast as “artists versus Big Tech.” But we must not forget that, at its core, copyright is a restriction on, as well as an engine for, expression.

Many try to cast the DMCA just as a tool to protect the rights of artists, since in theory it is meant to stop infringement. But the law is also a tool that makes it incredibly simple to remove lawful speech from the internet. The fair use doctrine ensures that copyright can exist in harmony with the First Amendment. But often, the debate gets wrapped up in who has the right to make a living doing what kind of art, and it becomes easy to forget how mechanisms to enforce copyright can actually restrict lawful speech.

Forgetting all of this serves the purpose of those who advocate for the broader use of copyright filters on the internet. And where those filters are voluntarily deployed by companies, they replace a fair use analysis. So a filter that automatically blocks a video for playing a few seconds of a song becomes a useful tool for police officers who do not want to be subject to video-based accountability. What’s the harm in automating the identification and removal of things that have copyrighted material in them? The harm is that you are often removing lawful speech.

It’s as easy to play a song out of your phone as it is to film with it. Easier, even. And copyright filters work by checking if something in an uploaded video matches any of the copyrighted material in its database. A few seconds of a certain song in the audio of a video could prevent that video from being uploaded. That’s the thing the cops in these stories are recognizing. And while it’s funny to see a cop playing Taylor Swift and claiming we can’t watch a video on YouTube that we are actually watching on YouTube, how many of these stories aren’t we hearing about? We know, without a doubt, that YouTube’s filter, Content ID, is very sensitive to music. And some singers and companies have YouTube’s filter set to automatically remove, rather than just demonetize, uploads with parts of their songs in them. Since YouTube is so dominant when it comes to video sharing, knowing how to game Content ID can be very effective in silencing others.

When a story like this gets press attention, the video at issue won’t disappear because everyone recognizes the importance of the speech at issue. Neither the platform nor the record label is going to take down the video of the cop playing Taylor Swift. But countless videos never make it past the filters, and so never get public attention. Many activists don’t know what to do about a copyright claim. They may not want to share their name and contact information, as is required for both DMCA counternotices and challenges to Content ID. Or, when faced with the labyrinthine structure of YouTube’s appeals system, they may just give up.

As the saying goes, we don’t know what we don’t know. Hopefully, these stories help others recognize and fight this devious tactic. If you have similar stories of police officers using this tactic, please let EFF know by emailing info@eff.org.