Blocks users from mapping host devices into containers. Whilst the ability to map devices is generally used for good (e.g. mapping a GPU into a container), it can equally be used by non-trustworthy authorized users to map a physical storage device into a container. It is possible to mount
/dev/sda1 into a container, and then from a console of that container, the user would have complete access to the sda1 device without restriction. By toggling this on, Portainer blocks the ability for non-admins to map ANY devices into containers.