1. A system comprising: an input to receive a content object posted to a web-based service, for distribution by the web-based service to the public; a hardware processing unit configured for: determining fingerprint data from a received content object, and by reference to the determined fingerprint data, determining that the received content object includes content that at least potentially matches controlled content; obtaining usage rule data relating to the controlled content, the usage rule data having earlier been established by an owner of the controlled content, the usage rule data comprising: i) an owner-specified extent of copying between the received content object and the controlled content, and ii) an attribution requirement for received content; determining an extent of copying between the received content object and the controlled content; determining whether the received content object meets a minimum percentage of content; and governing distribution of the content object based on the usage rule data including i) the owner-specified extent of copying between the received content object and the controlled content, and ii) the attribution requirement for received content, and on the determined extent of copying, when the received content object meets the minimum percentage of content; and an interface through which different owners can specify different extent of copying requirements to govern distribution of their respective content.