The Age reports on the development of a tool that creates PDFs which cannot be read if the computer attempting to read it is not online, and which reports to the publisher on how the document is distributed.
The company that's developing this is Remote Approach. I can't imagine the privacy and security implications should this become the main stream approach to software activation or data tracking. I would be very unsettled and for good reason too. Just check out the number of mishandled private and confidential data out there due to carelessness, lack of accountability and lack of financial incentive/disincentive.
Technorati tag: YC Privacy Security Schneier