This number is almost certain to increase if more Facebook users gravitate to making and watching videos, and chances are they will. In the company’s last quarterly conference call, back in February, Zuckerberg called video a “megatrend,” and, more widely, a recent report from Cisco indicated that mobile video traffic now makes up 60 percent of all mobile data traffic.

The use of artificial intelligence tools could help—Facebook is already adept at using AI to do things like figure out who specific people are in the photos you upload—but even Zuckerberg believes that’s a long way off.

In a long piece he posted to the social network in February, he said the company is looking into technology that can automatically flag photos and videos that shouldn’t be on the site, and said about a third of the reports to Facebook’s content-reviewing team currently come from AI-based alerts.

“It will take many years to fully develop these systems,” he said.

For now, at least, Zuckerberg is hoping that people can do the job that technology can’t. On Wednesday, he tried to point to a bright spot, though, saying that a week earlier the company was able to help stop someone from committing suicide on live video, as the company contacted police in response to a user report.

“In other cases, we weren’t so fortunate,” he said.