THIS is why I am not an advocate of keeping all your financial stuff ONLINE (if I'm understanding this correctly).....sure, have accounts at banks, brokerages, etc., but keep your own consolidated info to yourself.
In this case, the data is not online. Users can't get into files on their own computers. When Money is launched, it obviously communicates automatically with an update server, and the update server sent some crazy authentication routines that locked everyone out of their own local files.
MM