Security Mode, as the name suggests, is a high-security setting. When enabled, it will Disable Sleep, Enable Motion Detection and Recordings on all devices currently on your account; i.e. owned by you. (Cameras shared by other accounts will be unaffected).
Use this setting to detect and receive alerts on any suspicious movement. You can still override
individual camera settings like Enable Sleep mode and Mute Motion Notifications after Sleep Mode has been activated.