Few people understand computer security, and that's ok because it's complicated. It's not ok when said people are making laws related to it. This article explains why some of the things that government agencies want aren't actually feasible nor a good idea.
"Our business model is very straightforward: We sell great products. We don’t build a profile based on your email content or web browsing habits to sell to advertisers. We don’t “monetize” the information you store on your iPhone or in iCloud. And we don’t read your email or your messages to get information to market to you."
Facebook sucks when it comes to privacy. They walk the fine line between exposing all they can and pissing off your customers more than they should. I recommend you look into this script to help you verify your settings are properly configured.