Several assumptions underpin CPM theory (Petronio, 2002). For example, because both revealing and concealing carry a potential for vulnerability and because people feel they own their private information, they want to exercise control over it. CPM theory uses a boundary to represent the privacy management process in order to illustrate the way rules are used to regulate opening and closing of access. Privacy rules are dynamic; they change, grow, or remain stable for periods. (See Petronio, 2002, for additional assumptions.)