"I wanted to let you know something I just came across this evening; maybe you already know, but if not, I thought I would share.
I noticed on my wall (the button that is now your name next to home) that there was a history of every comment and wall post I made on my friends page. And by clicking it, a friend can read what I posted on a non friend.
example: If I am friends with MsRosie and LLCG but LLCG and MsRosie are not, MsRosie can still read LLCG's statuses if I commented on it or wrote on her wall. The way MsRosie can do this is if she was on my page and saw the history of what I wrote and clicked on it. It pulls up LLCG's status.
The way you can block this is go to your page and if you see your history, there should be an x next to it. Click where it says hide all comments. Then find a wall posting you have done and do the same thing. When you are done, the only thing showing on your page is the wall posts you yourself made. (your status updates)"