13. The computer-readable storage medium of claim 12 , wherein the predetermined trust criteria further include: (i) one or more past interactions between the third user and at least one of the first user and the second user, and (ii) a time of day when the communication is sent from the first avatar to the second avatar.
14. The computer-readable storage medium of claim 13 , wherein the predetermined trust criteria include at least one of: (i) a situation context of the first user within the virtual world, and (ii) a situation context of the second user within the virtual world.