Though I understand why everyone likes this idea, I see a basic flaw that concerns me.
What if some malware gains control of the PC and manages to shut down at least the firewall? Then what if that same malware were aware of how that stored personal information could be accessed? It could then simply take all of that information you've so conveniently entered and send it to the bad guys without even having to trick you into entering it.
Personally, I'd rather see more concentration on detecting and preventing the malware in the first place. If something has gotten on the system without being detected, collected information and is already in the process of trying to send it out it's quite possible that it could simply disable your protection anyway. So I don't really believe that having something monitoring what gets sent is necessarily all that valuable.
OneCareBear