1. A method comprising: by one or more computing devices, receiving an indication of a first user action by a first user; and by one or more computing devices, when the indication is received: determining a topic of the first user action based at least in part on analyzing content associated with the first user action; determining whether the first user has indicated a preference to exclude posts associated with the topic or a category associated with the topic; and in response to a determination that the first user has not indicated any preference to exclude posts associated with the topic or the category, then: identifying a second user action by a second user and related to the topic; determining whether the first user has indicated a preference to exclude posts associated with the second user; and in response to a determination that the first user has not indicated any preference to exclude posts associated with the second user, providing the first user with access to the second user action, wherein the access enables the first user to interact with the second user action.