I guess we now know what those chemtrail planes are spraying. Now, what is the purpose? ;-)

Have you looked into Adobe Acrobat server? It uses server side authentication to allow management of documents in real-time so you can add, change or remove rights to documents. It also allows for live update of content within documents to provide up-to-date stats and data. We have been evaluating it for our company. It isn't cheap but will probably be less than the legal cost of defending a lawsuit.