The Photo Booth app, included free with Apple's OS X operating system, is an easy-to-use program that takes still pictures and videos from your Mac's camera. You can also use Photo Booth as a "nanny cam," keeping tabs on activities in a room while you're away. For example, if you suspect your dog of sneaking food off the kitchen table, a MacBook running Photo Booth can catch the mischievous pet in the act.
Remove Photo Booth from the OS X dock by clicking the icon and dragging it off or by right-clicking the icon, selecting Options and unchecking the Keep in Dock menu item.
Click the Launchpad icon, then click Photo Booth to start the program.
Click the FIlm icon to put the program into video mode. Click the video camera icon to begin recording.
Click Photo Booth in the menu bar and select Hide Photo Booth. The Photo Booth window will disappear. Position your device so that the camera is pointed in the direction you wish to record.
Cut a small piece of electrical tape and place it over the green video recording indicator light; otherwise, the light will give away the fact that the Mac's camera is on.
Although it’s legal to video someone with their consent, state laws vary about hidden camera recordings; 13 states expressly prohibit the use of hidden cameras in private places. Video recording without consent may carry significant legal penalties, including incarceration, fines and exposure to civil lawsuits.