Many laptops have a built-in webcam and in the worst case, it can be used by hackers or authorities to spy on you.
A common solution among security-conscious people is to cover the camera when not in use, but this is something that Apple advises against in a recently published support document. If the cover is too thick, there is a risk of damaging the screen when the lid is closed.
That this is a real problem is confirmed by MacRumors, which has published a number of images on screens that have been destroyed by webcam coverings.
Apple also warns that camera covers can interfere with ambient light sensors and prevent functions from working, including automatic brightness and True Tone.
Normally you can see if the camera is on by activating an indicator light, but if you're still worried, you can set which programs are allowed to use the camera in System Preferences. You must be running macOS 10.14 or later.
This article originally appeared on Macworld Sweden. Translation by David Price.