1. A method for selectively allowing a user of a multi-user system access to a plurality of resources in a network, the method comprising: receiving a request originated from the user to transmit a message over the network to one of the plurality of resources; identifying, from a plurality of security zones, a security zone associated with the one of the plurality of resources; determining if the user is authorized access to the identified security zone; and forwarding the message over the network to the one of the plurality of resources only if it is determined that the user is authorized access to the identified security zone.