By the nature of that particular domain a lot of systems delivered important documents (often containing data of rather extreme commercial sensitivity) to custo

By the nature of that particular domain a lot of systems delivered important documents (often containing data of rather extreme commercial sensitivity) to customer organisations. A standard question I always asked was "given a URL that links to a document how do you authorise access" i.e. what happens if someone who is logged in to the site in question gets a link to a document and passes it to a friend via instant messaging.