1. A computer-implemented method for disseminating a plurality of real-time message streams to a respective user of a plurality of users in a real-time messaging system, performed on a server system having one or more processors and memory storing one or more programs for execution by the one or more processors, the computer-implemented method comprising: selecting, from the plurality of real-time message streams, a set of messages based at least in part on a focus specification associated with the respective user, the focus specification comprising one or more selection criteria specified by the respective user; sending to a respective client system associated with the respective user target messages comprising at least a subset of the selected set of messages; sending to the respective client system one or more instructions to display a tracking control for allowing the respective user to select at least one in the target messages as at least one anchor message for tracking; receiving a selection of the at least one anchor message; and sending to the respective user messages subsequent to the at least one anchor message in a thread associated with the at least one anchor message.