The Lock Screen Privacy Risk
Ubuntu Linux features a modern notification system that alerts you to incoming emails, chat messages, system updates, and calendar events. By default, Ubuntu continues to display these notification banners even when your screen is locked. While this allows you to glance at your monitor and see what you missed while getting a coffee, it represents a significant privacy vulnerability in a shared office or public environment. Anyone walking past your desk can read the subject lines of your private emails, the contents of your instant messages, or sensitive system alerts without needing your password.
How to Disable Lock Screen Notifications
You can easily instruct the GNOME desktop environment to hide all notifications whenever the screen is locked, ensuring your private data remains unseen until you authenticate.
1. Click on the system menu in the extreme top-right corner of your screen (where the battery and network icons are).
2. Click on the Settings icon (the gear).
3. In the left-hand navigation sidebar, click on Notifications.
4. At the top of the main pane, you will see a toggle switch labelled Lock Screen Notifications.
5. Click the toggle switch to turn it Off.
With this master switch disabled, your lock screen will only display the time and date. All incoming notifications will be silently queued in the background. You will only see them once you enter your password and unlock your session.
How to Hide Specific App Notifications
If you don’t want to completely disable all lock screen notifications—for example, maybe you want to see calendar reminders but want to hide private chat messages—you can configure this on a per-app basis.
Leave the main “Lock Screen Notifications” toggle ON. Then, scroll down the Notifications settings menu to see the list of individual applications. Click on the app you want to restrict (e.g., your email client or chat application). In the specific app’s settings menu, look for the toggle switch labelled Show Notifications on Lock Screen and turn it Off. This granular control allows you to balance convenience with privacy.