Patent ID: 8409007

Claim:
A server apparatus communicable with each of a plurality of operation devices that is operated by a plurality of users, respectively, comprising: a memory unit comprising a personal data area for storing data written therein and a personal relationship data area for storing data written therein; a personal data writer that writes into the personal data area public identifiers identifying the plurality of users and operation status data elements indicating statuses of operations on at least one of the operation devices, in such a manner that a public identifier for an individual user is associated with an operation status data element indicating a status of operation by the individual user; a self-public-identifier transmitter that transmits to a first user an information element imparting a first public identifier of the first user; a personal relationship data writer that, upon receiving the first public identifier from the second user, the first public identifier identifying the first user, writes into the personal relationship data area the received first public identifier of the first user in association with the second user; a transmitter that transmits to the second user an information element indicating an operation status data element of the first user stored in the personal data area and identified by the first public identifier of the first user associated with the second user in the personal relationship data area; and a public identifier changer for changing the first public identifier of the first user stored in the personal data area upon receiving a request for changing the first public identifier of the first user from the first user, wherein upon changing the first public identifier for the first user in the personal data area, the public identifier changer transmits to the first user an information element imparting a second public identifier of the first user different from the first public identifier, and wherein the public identifier changer does not update the first public identifier of the first user stored in the personal relationship data area with the second public identifier.