A resource controller may store a plurality of files or other data that are at least partially accessible by one or more users in a network. The user may operate a mobile device, such as a cellular telephone and/or personal digital assistant, to call or otherwise contact the resource controller. The mobile device and/or a communications network may send identification information to the resource controller that identifies the mobile device and distinguishes it from other mobile devices. Based on the identification information, the resource controller may grant or deny access to files. The resource controller may further provide the user with the appropriate user ID and/or password based on the identification information. The user may then enter the user ID and/or password to gain access to files stored at the resource controller.