The disclosure describes a data storage system that includes a signal defect correction system for removing signal defects in magnetoresistive head playback signals. One exercise device described is an inelastic resistance device having a combination grip that includes hand grips and a loop. In response to a request for a commercial message search in which a keyword sent from the user via a network is taken as a key, the CM information server searches the data base for a commercial-message feature and sends the commercial-message feature detected in the data base to the user via the network.