1. A wearable device comprising: a memory to store a plurality of device identifiers of a plurality of wearable devices belonging to a wearable device ensemble; a human body communication (HBC) transceiver to communicate over an HBC network via a body of a user, said HBC transceiver to receive via said HBC network one or more detected identifiers of one or more detected wearable devices on said body; and an ensemble manager to manage said wearable device ensemble, and to generate an alert based on a comparison between said one or more detected identifiers and said plurality of device identifiers.