1. A system, comprising: a display device; sensors configured to detect users that perform user commands proximate to the display device; a processor; and a computer-readable storage medium storing instructions which, when executed by the processor, cause the processor to: present a shared canvas on the display device; modify the shared canvas as multiple detected users interact in a collaborative effort on the shared canvas via the user commands; determine a relative confidence in an identity of an individual user of the shared canvas; detect an individual user command from the individual user; provided the relative confidence in the identity of the individual user is sufficient, present a private data portal on the shared canvas for the individual user in response to the individual user command; display an individual private data item on the shared canvas responsive to the individual user identifying the individual private data item via another individual user command directed to the private data portal; and remove the private data portal for the individual user responsive to detecting that the individual user is no longer interacting with the shared canvas.