‘Your screen is being observed’ message on Mac lock screen
When you’re using software to share or record your screen, the lock screen might show a privacy reminder that your screen is being observed by that software.
When you lock the screen of your Mac, the lock screen might include the message “Your screen is being observed.” The message can appear in these circumstances:
You’re using software that is sharing or mirroring the contents of your screen to another device. For example, you’re using the screen-sharing feature of a videoconferencing app, using AirPlay or other software to view your screen on an external display or TV, or allowing software such as Screen Sharing, Apple Remote Desktop, or other VNC app to remotely access your Mac from another device.
You’re using software that is recording your screen, such as a videoconferencing app, screen-capture app, or even the screen-recording feature included with your Mac.
If you have difficulty identifying the software or controlling its screen-sharing or screen-recording features, try these solutions:
Use macOS settings to control access to screen sharing and control access to screen recording.
Update macOS, which can include important security updates.
Restart your Mac.
If the message persists, you can use safe mode to learn whether the issue is caused by third-party software that loads as your Mac starts up.