A common description of the problem seems to be that the app opens up the camera mode while users watch videos or are looking at the newsfeed. Some experience the issue when they switch to fullscreen mode, which seems to call the camera view on the screen for a brief moment.
The earliest case of this was noticed over a week ago by someone who found that rotating the screen would also bring up the Story UI. The issue seems to affect iPhone users running iOS 13.2.2, which fixed a bug that killed background apps too aggressively.
Found a @facebook #security & #privacy issue. 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. pic.twitter.com/B8b9oE1nbl— Joshua Maddux (@JoshuaMaddux) November 10, 2019
Given Facebook's poor track record protecting user privacy, some consider this to be yet another reason to leave the platform. Guy Rosen, vice president of safety and integrity at Facebook, acknowledged there is indeed a bug where the app "partially navigates to the camera screen when a photo is tapped." The company has already submitted a fix to the App Store, and says it found no evidence the bug could lead to photos or videos being uploaded in the background.
The news comes just as the social giant revealed its own payment service that works with Messenger and Facebook, with plans to extend the functionality to WhatsApp and Instagram.
It's worth noting that Facebook has been making efforts to improve the app by allowing users to remove some of the visual clutter from the navigation bar. That said, iOS 13 now shows users just how hungry it is for their location data, so the company still has a lot to do if it wants to regain user trust.