I have always been rather careful with who I friend and what I share,
but I suspect this will be a nice reminder to a few people.

The latest changes to Facebook are groundbreaking (details here), but they also mean that now, more than ever, you should have a handle on who sees your stuff, and what that stuff is. So here are two cardinal rules of Facebook I strongly encourage you to follow:

First, it’s time to purge your friends list (and keep it clean).
You’ve hesitated for years. You’ve wanted to, but just couldn’t bring yourself to do it. I understand. It’s hard. You feel guilty. I understand, but it’s time. Because the new Facebook means two things: you’ll be sharing a whole lot more stuff, and everything you’ve ever shared will be exposed.
So yes, it’s time. You have to get rid of all these “friends” that aren’t really your friends. The drunk dude that you meant at that party once. The girl who’s updates you “like” sometimes, because she’s hot. That guy you knew in high school but haven’t talked to in fifteen years. Yeah, these aren’t your friends. Facebook a tool to communicate with the people in your life you care about, not a contest to get the biggest friend count. So seriously, do it now, or you’ll be sorry later.

Second, you shouldn’t post things that would sink you if they went public.
The question you should ask yourself before posting anything online is: “if this becomes public, am I ok with it?” If the answer is no, don’t post it. Not in your private BFF group, not as a secret picture to your boyfriend, not as a direct message to your mom. Nowhere. On the internet, nothing is ever truly safe. There are hacks, policy statements nobody reads, policy changes nobody understands, disgruntled a-holes out to get you, and much more.
So just do yourself a favor and assume everything you post could end up being public, and that’s it. Of course, that doesn’t mean you can’t share private stuff: it’s ok to share something private (baby pictures) with the right group of people (your folks). But if it’s something really private or shameful (I’ll let your imagination run wild here), do not post it, period. Ever. E-VER.