Abstract: Automatically associating users of a communication system, without using an invitation or affirmative permission. In one embodiment, a first user submits contact information about a second user to a relationship system, which stores the information in the first user's contact list. Similarly, a second user submits contact information about the first user to the relationship system, which stores the information in the second user's contact list. The relationship system detects the cross reference in the two contact lists, and stores a first degree relationship between the two users. One of the users submits a request to the relationship system to enable an operation with any other user that was associated with the submitting user. Associations can also be selectively higher degrees with other users. The submitting user need not know which other users will participate in the operation, and the other users need not know the submitting user's identity.