There was a flurry of stories some months back about rogue programs or hackers activating webcams that were external or built-in on desktop and Mac laptops. The stories left a lot of people with a queasy feeling, and recent NSA revelations have also called into question the security of our computers and mobile devices.
Camera Lock (US$2.99, currently 40% off) is an interesting Mac utility that enables you to lock out your camera and refuse access by any app. If the camera was already in use, the video freezes and the green LED starts flashing.
The app operates from the Mac menu bar, and lets you lock or unlock access to the camera. If unlocked, the app alerts you that someone or some app is trying to access the camera. The Camera Lock app can be launched at login, and there is a log that shows recent activity.
I tried the app on my MacBook Air and it worked as advertised. When locked, the camera simply would not work with apps including FaceTime and Messages. When unlocked, the green LED flashed when I accessed the camera.
Unsurprisingly, Camera Lock worked in an identical manner on my Mac Pro, which uses a Logitech external USB webcam. The LED flashed when it was accessed, but when the lock was on no other app could get to the video. When cameras are locked and unlocked, you get an on-screen notification and a sound.
I'm not sure how much of a threat people spying on you from your webcam is, but certainly it has been done and Camera Lock seems to prevent it smoothly and effortlessly. Of course any system can be bypassed by knowledgeable hackers, so the best protection against camera intrusion is to have no camera at all or put a piece of tape over it.
Camera Lock requires OS X 10.9 or later and a 64-bit processor.