Thursday, July 16, 2020

Don’t Close Your MacBook With a Camera Cover

Apple (via MacRumors, Hacker News):

If you close your Mac notebook with a camera cover installed, you might damage your display because the clearance between the display and keyboard is designed to very tight tolerances. Covering the built-in camera might also interfere with the ambient light sensor and prevent features like automatic brightness and True Tone from working. As an alternative to a camera cover, use the camera indicator light to determine if your camera is active, and decide which apps can use your camera in System Preferences.


The camera is engineered so that it can’t activate without the camera indicator light also turning on. This is how you can tell if your camera is on.

Even assuming there’s no way around that, the light only provides protection when you happen notice it. This will be some time—possibly short or possible very long—after the camera had started recording. If the software simply takes a photo and turns the camera back off, you might not notice the light flash even when sitting at the computer.

If you install a camera cover that is thicker than 0.1mm, remove the camera cover before closing your computer.

I’ve been using a piece of electrical tape, which Wikipedia says is between 0.18mm and 0.25mm thick. I’m not sure what you could use that would be thin enough to leave on.


None of the proposed solutions do anything to actually stop the camera from taking a picture of you. Sure, you’ll see the indicator light up for 3 seconds. But the attacker still got what they needed.

Camera covers have nothing to do with identifying compromise. They are strictly for preventing compromise. This is exactly opposite what a camera indicator light does, and thus the indicator should not be considered a “workaround” for not being able to install a camera cover.


I was very skeptical of the camera covers, but then through conversations with some of my co-workers, I realized that they weren’t being used because people were worried about spies secretly turning on the camera. It was 90% of the time just peace of mind that their camera was actually off, instead of having to find the sometimes hard to see options in video chat programs etc.


Update (2020-07-29): Simone Manganelli:

Even if there were a big omnipresent, easy-to-access button in the menu bar that would turn off the camera, sometimes the OS hangs, or is slow to respond to a button click, and those seconds can be make-it-or-break-it for a huge embarrassment.

5 Comments RSS · Twitter

Rand Arnold

Doen't cover your camera, but does let you know if a process is using it or your microphone:

It does have limitations though.

I've been using a clipping from the sticky part of a Post-it note. I just measured a fresh, unused 70-sheet Post-it note pad with my calipers at about 7.4±0.1 mm. That comes out to about 0.105 mm per sheet. I can tell by feel that it's thinner than the metal lip around my 16" MacBook Pro screen.

I recently ordered some CamTags (haven’t got them yet). They’re made by the company that made TabTags, the stickers that went over the glowy Apple logo on old MacBooks. They’ve addressed this and say that they are within Apple’s limits.

>It was 90% of the time just peace of mind that their
>camera was actually off, instead of having to find
>the sometimes hard to see options in video chat
>programs etc


I use a lot of different video conferencing apps, and it's not always clear to me if the camera will turn on when I join a call. Often, these apps just remember the setting from the last call, which is also not really helpful, since I usually don't remember whether the camera was on in my last call in that particular application.

Having physical control over the camera makes this easy.

The fact that this also helps defend against spyware is nice, but for many people, the bigger problem there is the microphone.

I use some stickers they used to sell. I don't care if its too thick or whatever. I want that camera covered up.

Leave a Comment