Smartphone users are at risk of maxing out their data plans if they don’t change this default setting in the Facebook app, which otherwise will automatically start streaming videos in the News Feed window.

If you’re an iPhone user, tap your “Settings” button and then scroll down and click “Facebook.” From there, click “Settings,” “Auto-play,” and then choose “Wi-Fi only” or “Off.”

On Android, bring up the Facebook app and go to your account settings. Click “App Settings,” and then choose ‘Auto-play only on Wi-Fi’ or ‘Off.’