Presence-based content control

Presence based content access control techniques are described in which presence of users is used as a basis for enforcing content restrictions. In an implementation, applications are registered to receive feedback regarding users' presence in relation to a presentation of content via a computing device. The presence of users is recognized independently of authentication of the users to access user accounts. For example, an imaging sensor such as camera may be employed for recognition of multiple users engaged with the computing device. In addition or alternatively, presence devices associated with users such as badges, key fobs, or access cards may be detected to ascertain the presence of users. Feedback indicative of the one or more users that are recognized may then be supplied to the registered applications. The feedback enables the applications to control the presentation of content by enforcing content restrictions and/or taking other presence based actions.