1. A method comprising: receiving, by one or more computing systems, a first user action relating to a first topic from a first user; identifying, by the one or more computing systems, the first topic based on the first user action; identifying, by the one or more computing systems, one or more second posts that relate to the first topic, each of the second posts having been received from other second users; and transmitting, by the one or more computing systems, to the first user, one or more of the second posts or information associated with the second posts in a structured document for display to the first user, the structured document further comprising one or more interactive elements that enable the first user to interact with the one or more second posts or to respective second users that declared the second posts.