14. A non-transitory computer-readable storage medium having collectively stored thereon executable instructions that, when executed by one or more processors of a computer system, cause the computer system to at least: receive an access control policy specifying privileges of one or more users for accessing at least one document maintained by a document management and collaboration system, the privileges of the one or more users having been expanded by a first user; formulate a set of recommended access privileges for the one or more users based at least in part on one or more attributes associated with the one or more users, at least one attribute of the one or more attributes is a measure between a first character map corresponding to the at least one document and a second character map corresponding to a particular user of the one or more users; request the first user to accept the set of recommended access privileges of the one or more users; and in response to the request, set the privileges of the one or more users to a privilege level specified by the first user and based at least in part on the set of recommended access privileges.
18. The non-transitory computer-readable storage medium of claim 14 , wherein the instructions further comprise instructions that, when executed by the one or more processors, cause the computer system to identify at least one user of the one or more users due at least in part to a duration of time elapsing from access by the at least one user to a document exceeding a threshold.