1. A method of presenting facts extracted from a social network on a device having a processor and a fact store, respective facts associated with at least one topic, the method comprising: executing on the processor instructions configured to: upon receiving from a user within the social network a message conveying a personal opinion of the user: identify in the message a reference identifying a topic associated with the personal opinion, translate the personal opinion in the message into at least one fact associated with the topic identified by the reference and not explicitly stated in the message, and store the fact in the fact store associated with the topic; and upon receiving from a user a query related to a topic: select from the fact store at least one fact associated with the topic, and present the at least one fact to the user.