Fast user switching allows several users to use one Mac without completely log out of all other users. From time to time we see memory or file permission bugs. Exploits can give you access to user and even kernel memory or disk. When fast user switching is used, another experienced users can get access to data in memory or on disk.
How to fix it
macOS 13 - 14
- Open “System Preferences”
- Go to “Control Center"
- Deselect “Show in Menue Bar”
- Deselect “Show in Control Center”
macOS 10.11 – 12
- System Preferences > Users & Groups > Login Options
- Deselect “Show fast user switching menu as”

