US Patent 10122727 Social networking behavior-based identity system

Disclosed are various embodiments for a social networking behavior-based identity system that employs social networking data that a user has elected to share through an opt-in procedure. First social networking data is stored in association with a user identity. An assertion of the user identity is received from a client after the first social networking data is stored. Second social networking data is received in response to receiving the assertion of the user identity. An identity confidence level as to whether the user identity belongs to a user at the client is generated based at least in part on a comparison of the second social networking data with the first social networking data.