Patent ID: 8656463

Claim:
A method comprising: maintaining a trust level for each of a plurality of users of a social networking system, wherein each user's trust level represents a global trustworthiness of the user in the social networking system; receiving a telephone number from a user of the plurality of users; sending a message to a device associated with the telephone number; receiving a response to the message; determining if the response meets a criterion; confirming that personal information under the control of the user has not been used to verify another user of the social networking system; increasing, by a computer system of the social networking system, a trust level associated with the user if the response meets the criterion and if the personal information under the control of the user has not been used to verify another user of the social networking system; receiving a request from the user to send a message to one or more other users via the social networking system; and determining whether to allow the request to send the message based on the trust level maintained by the social networking system for the requesting user.