For the second time this summer, Facebook has made a major change to its News Feed guidelines. The company will now reduce the rank and reach of headlines that it considers to be clickbait, because it believes that these deceptive headlines erode the “authentic communication” that happens on the platform.

“These are headlines that intentionally leave out crucial information, or mislead people, forcing people to click to find out the answer,” write two researchers who work for the company. They rattle off some examples:

“When She Looked Under Her Couch Cushions And Saw THIS… I Was SHOCKED!”

“He Put Garlic In His Shoes Before Going To Bed And What Happens Next Is Hard To Believe”

“The Dog Barked At The Deliveryman And His Reaction Was Priceless.”

Facebook is a vast platform, so its employees can’t identify all the headlines that lurk there one at a time. Instead, they have developed a system that identifies them automatically. An algorithm knows certain phrases that usually indicate clickbait and punishes them accordingly. “Links posted from or shared from Pages […] that consistently post clickbait headlines will appear lower in News Feed,” they write.

This could potentially be very good for readers and for the journalists who work hard to inform them. But at the same time, we don’t really have a choice about whether to comply. Along with Google, Facebook wields incredible power in the marketplace: By one estimate, the two companies direct 80 percent of all traffic to news websites. Two years ago, the late media columnist David Carr fretted that news publishers would soon become “serfs in a kingdom that Facebook owns”; today, not only do we find ourselves ensconced in Castle Facebook, but the local lord’s laws and guidelines are not written on paper, but executed impersonally and algorithmically. Journalists have to guess to make sure that we’re not doing anything wrong.