How do you do real time document tracking?

Question

I was considering diff Document Tracking options and came across DocTracking.com. DocTracking.com allows you to upload documents (PDF Word etc) and adds some kind of invisible tracking to it and returns the document to you which can then be used just like you would use the document otherwise. This tracking tells you when your documents were opened, who opened them (IP), geo-location of opening if they are re-opened or forwarded, what pages were read and how long it was read for, what was printed. Any leads on how this could be done would be appreciated.

Answer 1

It may be possible to embed an internet control/image into the document so get the client application to send an HTTP request to the server, which can use the request to identify the document and link it to the IP address (and consequently location). Various degrees of logic can be embedded for more sophistication.

Of course, the won't work if someone's Word, let's say, is firewalled.

That's one of the ways I can think of to make something like doctracking.com's system work. I doubt that there is anything built into Acrobat or Word to let a document stream data from the host PC, seems massively unsafe.