Users of the Facebook app have complained after discovering a bug that causes their iPhone cameras to activate in the background when they use the app. 

Multiple people have taken to Twitter to report that using the Facebook app on their iPhone has caused the device’s rear camera to switch on and run in the background.

Eagle-eyed users noted that the problem seemed to occur as they looked at photos and watched videos that appeared on their newsfeed.

It isn’t clear whether the cameras activated by the bug were recording what they observed.

The earliest incident relating to the bug was recounted on Twitter by software tester @neo_qa on November 2. 

The concerned Facebook user wrote: “Today, while watching a video on @facebook, I rotated to landscape and could see the Facebook/Instagram Story UI for a split second. When rotating back to portrait, the Story camera/UI opened entirely. A little worrying . . .”

CNET were able to replicate the bug, and other Facebook users chimed in to say that they had experienced the same issue, with one Twitter user, @selw0nk, quipping that “It’s not a bug, it’s a feature.”

At the beginning of this week, more users of Facebook took to Twitter to report another bug that seems to be affecting the latest version of the iOS. 

This time, users said that when they navigated away from an image they had opened in the Facebook app, they could see a thin slice of the camera’s viewfinder. From this, they concluded that whenever the Facebook app is opened, the camera is activated in the background.

Twitter user @JoshuaMaddux wrote on November 10: “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.”

The camera-related bugs have added fuel to the fire for people who believe that it’s within the realm of possibility that Facebook might deliberately record its users as a way to gather information or target advertisements. 

After a week of silence regarding the first camera bug, Facebook’s vice president of integrity Guy Rosen responded on Twitter to Maddux’s November 10 tweet about the second bug. 

From his Android device, Rosen wrote: “Thanks for flagging this. This sounds like a bug, we are looking into it.”

In a later tweet, Rosen said the camera bug had been created when an earlier bug was fixed.

“We recently discovered our iOS app incorrectly launched in landscape,” Rosen wrote. 

“In fixing that last week in v246 we inadvertently introduced a bug where the app partially navigates to the camera screen when a photo is tapped. We have no evidence of photos/videos uploaded due to this.”

Rosen later confirmed that nothing was uploaded to Facebook as a result of the camera-related bugs, because the camera was in preview mode. 

A fixed version of the app was submitted to the App Store yesterday.

Dr. Richard Gold, head of security engineering at Digital Shadows, commented: “Bugs such as these erode the already fragile trust between companies and the public, even though their origin might be completely innocuous.”