The invention provides one or more consortia of networks that identify and share information about users and/or user devices interacting with the consortia. User devices may be identified, at least in part, by a delta of time parameter between a user device used and a reference time. Other parameters may be analyzed to identify a computer user and/or device and noteworthy transactions. The invention may be used for identity-based applications such as network security, the detection of fraudulent transactions, identity theft, ratings-based communities and law enforcement. User may be permitted to register user devices in order to control access for performing transactions.