Information processing apparatus, information processing method, computer program, and information sharing system

An information processing apparatus that can communicate with plural content viewing apparatuses via a network, the information processing apparatus comprising:

• a group registering unit that registers users of the content viewing apparatuses in groups;
• a sharing-level setting unit that sets, on the basis of level setting instructions received from the content viewing apparatuses, sharing level information representing an information sharing level among users belonging to an identical group;
• a viewing-information receiving unit that receives viewing information of the users in the content viewing apparatuses from the content viewing apparatuses;
• a user-viewing-content managing unit that manages, on the basis of the viewing information received from the content viewing apparatuses, a user viewing content database in which plural contents that can be provided to the content viewing apparatuses and users who view the contents are associated;
• a discriminating unit that discriminates, when a viewing information request of another user is received from the content viewing apparatus, on the basis of the sharing level information, the other users belonging to a group identical with a group to which the user of the content viewing apparatus at the request source belongs;
• an information extracting unit that extracts viewing information of the discriminated other users from the user viewing content database;
• and
• a viewing-information transmitting unit that transmits the viewing information of the discriminated other users to the content viewing apparatus at the request source.