It is a big issue to keep you safe on Internet. I do use Facebook, Twitter, Myspace etc. The first step after signing up in these website is take a look at Settings, or Privacy settings.
Remove every unnecessary sharing, make sure use the different password or user name.
For myself, I am not worry about the trustfulness on Facebook. But the third party, or apps providers are not 100% trustful. When I connect the app, I will look at it closely.
There is no secret on Internet. Anything you post on the web site like Facebook, may have chance to spread to everyone. If one person can see it, it is a lot of possibility that more and more people will see it.
When you post a video on the web site, any one can download it, or save it. Even you delete it from the original place. Any one has the copy of your video can re-post it. No way to stop it.
So not just on Facebook, any website, we have to very caution when we want to say something.
I read Parents Aren’t Worried About Facebook Privacy, Partly Because They Don’t Understand It
As a parent, you should know more than your kid about the privacy issues. Tell them how to protect themselves.
I don not think any kids below 13 years old can have a BBS account, Facebook account or any other social network user account. They may have email account, a blog.
Google it, you will find more related articles.