Facebook Privacy too confusing?

[Ahab]

I don't want people in my friend's lists getting updates on of comments I made on other people's updates/photos/posts/everythingelse. Say for example, I wrote on a public figure's wall or commented on their posts...it apparantly shows in all my friend's news feeds. And even stuffs I've written on my friend's walls can be seen in all of my friends' feeds even if they're not friends with the person whose wall I posted on.

Can I stop that from happening?