Abstract: The subject matter of this specification can be embodied in, among other things, a computer-implemented method for controlling access to user-related data including electronically registering a plurality of data providers with a computer-implemented data exchange. The method further includes electronically registering a plurality of data buyers with the computer-implemented data exchange. The method further includes mediating a data sharing arrangement between one or more of the data buyers and one or more of the data providers, the data sharing arrangement defining prices and permitted uses of data provided by the one or more data providers to the one or more data buyers. The method further includes enforcing, on behalf of the one or more data providers, one or more restrictions imposed by the data sharing arrangement on the one or more data buyers.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for receiving data including a user identifier associated with a user and one or more key-value pairs associated with the user's access of a resource. Each key-value pair includes a key and a value provided by the resource. Upon determining that the received data satisfies one or more rules associated with a user list comprising user identifiers, the user identifier is added to the user list.

Abstract: Systems and techniques are described for splitting user-lists. A described technique includes obtaining a master user-list, the master user-list including object identifiers that are respectively associated with web clients; obtaining a splitting factor that controls a splitting of the master user-list; creating a reduced user-list from the master user-list based on the splitting factor such that the reduced user-list maintains a statistical fidelity of the master user-list, the reduced user-list including fewer than all of the object identifiers included in the master user-list; and providing the reduced user-list.

Abstract: The subject matter of this specification can be embodied in, among other things, a computer-implemented method for controlling access to user-related data including electronically registering a plurality of data providers with a computer-implemented data exchange. The method further includes electronically registering a plurality of data buyers with the computer-implemented data exchange. The method further includes mediating a data sharing arrangement between one or more of the data buyers and one or more of the data providers, the data sharing arrangement defining prices and permitted uses of data provided by the one or more data providers to the one or more data buyers. The method further includes enforcing, on behalf of the one or more data providers, one or more restrictions imposed by the data sharing arrangement on the one or more data buyers.

Abstract: A computer-implemented method comprises receiving a request for content from a user, determining a user list associated with the user, the user list including a definition that characterizes members of the user list, determining additional data related to a context associated with the user, and providing user list definition data and the additional data along with the request to a consumer that has subscribed to the user list.