1. A method that facilitates file access control of a network storage service, the method comprising: providing a third-party application database comprising third-party software application descriptions, each third-party software application description including, application title, client ID, supported Multipurpose Internet Mail Extensions (MIME) types and an associated application-specific ID; providing a user data store comprising files associated with users, each file within the user data store having an associated MIME-type containing an application-specific ID and a file identifier; receiving a file access request at the storage service over a communication network from a third-party application operating on a computing device, the access request including a client ID for the third-party application and a file identifier for a specific file; determining an application-specific ID for the third-party application by performing a query in the third-party application database to select a particular third-party software application description that includes the received client ID included in the file access request; locating a file from the user data store having a file identifier that matches the received file identifier included in the file access request; extracting an application-specific ID from a MIME type associated with the located file; and granting access to the requested specific file in the user data store to the third-party application in response to a determination that the determined application-specific ID for the third-party application matches the extracted application-specific ID.