Is private really private?

After reading the article "Myspace Bug Leaks", I was shocked. The article discussed a new "backdoor" method which allows virtually anyone to view peoples' private myspace profiles. This means that even if myspace users are setting their profiles to private, they are still open to anyone who desires to see their posts, photos, etc.. However, the greatest problem with this new method is not only the lack of privacy, but the new ability for pedophiles and creeps to view pictures and profiles belonging to users under the ages of 16!
When I was finished reading this article I was some what relieved that I have never been a user or created an account for myspace. I thought, "man I'm glad this couldn't happen to me". But, after awhile I came to another realization; "If it it is that easy for anyone to look at private myspace accounts, why shouldn't it be that easy to access private facebook accounts (which I have)". I logged into my facebook account and went to a tab I never really paid much attention to before: security settings. Previous to reading the article I was under the impression only friends can view my profile.....Thankfully, I rechecked all my security settings, made a few adjustments and I was relieved yet again. In retrospect it seems all to plausible to assume there are quite a few people with the ability to look at private facebook accounts. I guess the only way to beat the problem is to make sure your smart about what you put online about yourself and remember who can see it...