1. A system for controlling distribution of information stored on a network, comprising: a data store including a database; and a hardware processor configured to (1) receive data units, each including an information object, from a community of users via a network, (2) store in the database the received data units, with each data unit being stored in association with an identifier of the user in the user community from whom the applicable data unit was received and a sharing (S) limitation parameter, wherein the stored data units include a first stored data unit received from a first user in the user community, (3) receive an inquiry, directed to the first user, requesting information relevant to a particular subject, from a second user in the community via the network, (4) direct transmission of the received inquiry to the first user via the network, (5) receive, via the network in response to the transmitted inquiry, authorization of the first user to share the stored first data unit with the second user, (6) receive, subsequent to receipt of the first user share authorization, a request to access the stored first data unit from the second user via the network, (7) allow, based on the received first user share authorization and in response to the received access request, the second user to access the stored first data unit via the network, (8) receive, via the network, authorization of the second user to share the stored first data unit with a third user in the community of users, (9) receive, subsequent to receipt of the second user share authorization, a request to access the stored first data unit from the third user via the network, (10) deny, based on the stored S limitation parameter and in response to received third user access request, access to the stored first data unit by the third user, (11) receive, from the first user via the network, revocation of the first user share authorization, (12) receive, subsequent to receipt of the first user share revocation, another request to access the first data unit from the second user via the network, and (13) deny, based on the received first user revocation and in response to the received other access request, access to the first data unit by the second user.