That's why folks have been able to pull up other guests' personal information and vacation plans since the new site went live (and some have been paid off for their problems, but without even a note or letter included with the gift cards because Disney knows that would open up liability in a legal sense).
A few weeks before our vacation, when I logged into the Disney website, it asked me to completely recreate my profile, pretty much from scratch, and then relink everything. I wonder if that is related to those issues? We never experienced the problem, but obviously, enough did that may have prompted them to take this step, and start over.