An apparatus comprising: an interface configured to receive a respective uplink data stream from each of three or more further apparatuses, and for transmitting a respective downlink data stream to each of the further apparatuses; and a control system in communication with the interface, the control system being configured: to receive first data in the uplink data stream received from a first one of the further apparatuses; in a first mode, to include at least some of the first data in the respective downlink data streams transmitted to every other one of the further apparatuses; and in a second mode, to include at least some of the first data in the downlink data stream transmitted to a second one of the further apparatuses and to omit or attenuate substantially all of the first data in the downlink data stream transmitted to at least a third one of the further apparatuses, CHARACTERISED IN THAT the control system is further configured: to determine that the first one of the further apparatuses is joining, after a period of absence whose duration exceeds a threshold, an existing virtual meeting hosted by the apparatus; to transition into the second mode in response to the determination; and to select, at least provisionally, one or more of the further apparatuses to receive, in the second mode, said at least some of the first data, wherein said selection is based on one or more system-related parameters and/or one or more meeting-related parameters. an interface configured to receive a respective uplink data stream from each of three or more further apparatuses, and for transmitting a respective downlink data stream to each of the further apparatuses; and a control system in communication with the interface, the control system being configured: to receive first data in the uplink data stream received from a first one of the further apparatuses; in a first mode, to include at least some of the first data in the respective downlink data streams transmitted to every other one of the further apparatuses; and in a second mode, to include at least some of the first data in the downlink data stream transmitted to a second one of the further apparatuses and to omit or attenuate substantially all of the first data in the downlink data stream transmitted to at least a third one of the further apparatuses, CHARACTERISED IN THAT the control system is further configured: to determine that the first one of the further apparatuses is joining, after a period of absence whose duration exceeds a threshold, an existing virtual meeting hosted by the apparatus; to transition into the second mode in response to the determination; and to select, at least provisionally, one or more of the further apparatuses to receive, in the second mode, said at least some of the first data, wherein said selection is based on one or more system-related parameters and/or one or more meeting-related parameters. to receive first data in the uplink data stream received from a first one of the further apparatuses; in a first mode, to include at least some of the first data in the respective downlink data streams transmitted to every other one of the further apparatuses; and in a second mode, to include at least some of the first data in the downlink data stream transmitted to a second one of the further apparatuses and to omit or attenuate substantially all of the first data in the downlink data stream transmitted to at least a third one of the further apparatuses, CHARACTERISED IN THAT the control system is further configured: to determine that the first one of the further apparatuses is joining, after a period of absence whose duration exceeds a threshold, an existing virtual meeting hosted by the apparatus; to transition into the second mode in response to the determination; and to select, at least provisionally, one or more of the further apparatuses to receive, in the second mode, said at least some of the first data, wherein said selection is based on one or more system-related parameters and/or one or more meeting-related parameters. to determine that the first one of the further apparatuses is joining, after a period of absence whose duration exceeds a threshold, an existing virtual meeting hosted by the apparatus; to transition into the second mode in response to the determination; and to select, at least provisionally, one or more of the further apparatuses to receive, in the second mode, said at least some of the first data, wherein said selection is based on one or more system-related parameters and/or one or more meeting-related parameters.