1. A presence agent system for processing requests to access presence information of a first computing device, comprising: a processor for executing computer executable instructions; and computer storage media storing: a component that receives from a second computing device a request to subscribe to presence information of the first computing device; a component that stores an indication that the second computing device has requested to subscribe to the presence information of the first computing device; a component that determines whether to accept the request of the second computing device to subscribe to the presence information of the first computing device; a component that when the request is accepted, sends to the second computing device an indication that the subscription has been accepted and the presence information of the first computing device; and a component that when the request is not accepted, sends to the second computing device an indication that the subscription has been accepted without sending the presence information of the first computing, the second computing device being allowed to subscribe to the presence information of the first computing device without gaining access to the presence information; wherein the determination as to whether to accept the request of the second computing device is made using an access control list provided by the first computing device; and wherein the access control list indicates to prompt the first computing device whether to accept a request from the second computing device.