A computing device includes a face detection module coupled to a webcam. The face detection module detects faces of viewers within a field of view of the webcam, provides images of the detected faces to a face identification service, and receives user IDs on the detected faces that have been identified. A document viewer module retrieves a document for display, with the document being retrieved based on a link to the document. A policy enforcement module receives the user IDs on the detected faces that have been identified, uses the link to the document to query metadata associated with the document to determine an access control list for the document, and compares the user IDs of the detected faces that have been identified to user IDs on the access control list to determine authorized viewers of the document. The policy enforcement module obscures display of the document if one of the identified faces is not authorized to view the document.