The invention features various techniques for managing transfers of information in public packet switched communications networks. In one aspect, the invention provides a system for identifying updated items of network-based information, such as pages, to users in a network. A master server receives the data from each of a plurality of network servers and merges them into one or more master logs. The logs have entries that pertaining to creation of or changing of pages of information. Another aspect of the invention features a system for implementing security protocols. A proxy server translates links from a protocol incompatible with the network tool to a protocol compatible with the network tool and back-translates the link. Another aspect of the invention features a system for managing authenticating credentials of a user. A proxy server manages a user's authenticating credentials automatically on behalf of the user. Another aspect of the invention features a system for inducing advertisers to target advertisements to consumers. An advertising broker receives advertisements and messages indicating that users have read the advertisements, and causes an offer having monetary value to be executed. Another aspect of the invention features a system for extracting data from sources of network-based information in a communications network. An object embedding-program locates a script program and causes the script program to extract data from a page of information.