Systems and methods for the forming of user device groups are presented. First, logical relationship information describing logical relationships among a plurality of users is accessed. Then potential membership of a first user of a first user device in a first group of users is determined based on the logical relationship information, by selecting the first group from a plurality of possible groups, the selecting being based on scores generated, for each of the plurality of possible groups, by a candidate scorer module, the scores based at least partially on information about the first user device, but the scores not being based on any personal information about the first user the first group of users containing a plurality of users, including one or more users who are not logically connected to the first user. Then the first user is added to the first group of users.