Login credentials for at least one website, such as a social networking website, are received from a user purporting to act on behalf of an entity, for example, in the context of registering the entity with a system for electronic bill payment. Social data relating to the entity is retrieved from the websites using the login credentials. The social data comprises a plurality of social connections, each reflecting a respective relationship between the entity and a respective third party. A plurality of relevant social connections comprising at least a subset of the plurality of social connections is determined, each social connection of the plurality of relevant social connections reflecting a relationship to a respective third party that is deemed to be reliable. A reliability rating of the entity is then determined based on the plurality of relevant social connections.