Thanks to AR, VR, and digital impersonation we can’t trust what we see and hear.

When scrolling through their Facebook feed, the average user won’t tend to see beheading videos, human genitalia, or brutal child abuse amid their standard content engagement announcements, cute animal videos, or even heated political spats.

There’s a reason why most people’s Facebook feeds are relatively sanitized. A documentary that premiers on TV Nov. 12 in the US is a stark reminder that a large group of real human beings are tasked with making the internet palatable for the rest of the world’s population.

The Cleaners is the first film by two German filmmakers, Moritz Riesewieck and Hans Block, and will be broadcast on PBS at 10pm US Eastern time, having debuted earlier this year at the Sundance Film Festival. The documentary follows a group of content moderators in the Philippines, where platforms like Facebook and YouTube outsource a large chunk of their review operations, with commentary from with experts and former executives.

The film is dramatized, with the moderators often shown at night, in empty, dark office buildings, narrating the footage with a monotone “delete, delete, ignore, ignore, ignore,” as computer monitors illuminate their faces. But no flashy dramatic effects are necessary to show the horrors of what these people have to deal with.

As one moderator in the film says, “this job makes you think violence is normal.” The moderators become experts at the most violent content out there, discerning corpses by the type of weapon used in the beheading. The film describes a harrowing story of one moderator who reportedly took his own life after repeatedly asking to be transferred from the team he served on. His coverage area was live self-harm content, including suicide attempts.

At the same time, some of the moderators see themselves as those who safeguard the internet. To do this job, you have to “have principles,” one of them says.

In the end, as Bryan Bishop aptly put it at The Verge, the film ends up being about how horrible the internet is, not merely about how horrible these people’s jobs are. It shows what happens, when, as Facebook CEO Mark Zuckerberg says in a speech poignantly shown in the movie, you “give anyone in the world the power to share anything with anyone.”

The documentary grapples with the central tension that plagues internet platforms: free speech versus clean discourse. It does so not just by interviewing experts, but also juxtaposing stories of people censored by the platforms—like an artist who drew an imagined portrait of a naked Donald Trump—with those at the end of the decision-making chain, the moderators who try to follow the platforms’ rules. The major technology companies face an often impossible question: when is something worth keeping up, and when should it be taken down? Who should be dictating these rules?

It doesn’t offer a direct answer, but it questions how we got here in the first place.