It doesn't matter that the system used a secure password encryption mechanism since it was possible to sneak in elsewhere. Once the hard security system has been passed, everything lays open to the intruder. Soft security expect and even accept that there might be unwanted intruders in the system. The idea is to identify them and prevent them from harming the other actors. There shall never be a key that uncritically opens up all locks on the system.
Social control is therefore a soft security mechanism.
An actor is accepted as long as her actions aren't harming anyone else, but if her behaviour changes, she will loose the ability to act, accordingly. In this paper we use the terminology actor when it is unimportant whether it is a human or a computer program who is acting, and we reserve the term agent for computer programs. There is a difference between how a system of actors and a system of agents can be allowed to function. In a pure agent system we can allow economic mechanisms to remove agents from the system, mechanisms that could be devastating if they were used on real persons. We also use the term agent when we describe related work in agent oriented computing.