Joshua Maddux, a twitter user, tweeted about the Facebook app using iPhone’s camera without authorization continuously while the app is open. He mentioned in his tweet that when the app is open it actively uses the camera.
“I found a bug in the app that lets you see the camera open behind your feed. Note that I had the camera pointed at the carpet.” he said pointing at the video he uploaded in his tweet.
He also mention that he has been able to confirm this across 5 different iPhones all running iOS version 13.2.2. He also told his followers that iPhones running iOS 12 don’t show the camera (not to say that it’s not being used).