Linux 5.4 Bringing Support For Lenovo's "PrivacyGuard" On Newer ThinkPads
Newer high-end Lenovo ThinkPad laptops feature an option called "PrivacyGuard" for restricting the usable vertical and horizontal viewing angles of the LCD display, similar to what has been achievable previously using film covers and the like. With Linux 5.4 this feature will be supported by the kernel if concerned about others looking over your shoulders at your screen, etc...