When I started with LJ four (!) years ago, I didn't use private posts at all, and I sorta figured, well, it's (i.e., LJ's) just bradfitz, and he seems like a good guy; I can trust him. Sure, he has access to the full database, but he wouldn't really have any reason to bother reading my private stuff, if I ever get around to actually posting that.
Now... well, clearly there are more people who could reasonably be expected to have access to the database. I honestly don't think that my data would be misused, but you can see how the questions would be raised.
Note that it doesn't even have to involve intentional snooping. I sometimes fill a sysadmin role in my own firm, and I don't intentionally look at people's email or anything. But there are certainly times when there is a legit problem that requires that I look at timestamps or whatever, and, well, the data is right there. I'll always try to use grep and the like to only view what I truly need, but that's not always possible. I'm just saying all of this to show how insiders can innocently expose themselves to private information, rather than there necessarily being any evil intent.