InformationHot corners _MUST_ be disabled.
The information system conceals, via the session lock, information previously visible on the display with a publicly viewable image. Although hot comers can be used to initiate a session lock or to launch useful applications, they can also be configured to disable an automatic session lock from initiating. Such a configuration introduces the risk that a user might forget to manually lock the screen before stepping away from the computer.
SolutionThis is implemented by a Configuration Profile.
mobileconfig profile info: