So how do you think that The Associated Press was able to obtain blacked out information from the settlement document concerning Facebook and ConnectU : copy and paste!
It is a bit of a joke obviously to talk about security in this case...
The document indicates a large difference in the valuation of Facebook depending on whether you take Facebook's internal valuation of the company: $3.7 billion as opposed to Microsoft's valuation of the company at $15 billon.
You can see the document here (at the moment) and on page 46 for example if you copy everything from lines 11 to 15 you will see the information that has been redacted by pasting it into a simple notepad application.
Amusing...