I just saw this post on Facebook which if you follow it's recommendations actually steps your friends through removing themselves from seeing your posts and comments. I don't know if it's on snopes.com yet, but I'm sure it'll be there soon.
The statement goes like this (i added highlights to show the flags that should make you suspicious of the content).
HEADS UP!!! FACEBOOK HAS CHANGED THEIR PRIVACY SETTINGS ONCE MORE!!! DUE TO THE NEW “GRAPH APP” ANYONE ON FACEBOOK (INCLUDING OTHER COUNTRIES) CAN SEE YOUR PICTURES, LIKES, AND COMMENTS. The next 2 weeks I will be posting this, and please once you have done it please post DONE! Those of you who do not keep my information from going out to the public, I will delete you! I want to stay PRIVATELY connected with you. I post shots of my family that I don't want strangers to have access to!!! This happens when our friends click "like" or "comment"... automatically, their friends would see our posts too. Unfortunately, we cannot change this setting by ourselves because Facebook has configured it that way. PLEASE place your mouse over my name above (DO NOT CLICK), a window will appear, now move the mouse on “FRIENDS" (also without clicking), then down to "Settings", click here and a list will appear. REMOVE the CHECK on "LIFE EVENTS" and "COMMENTS & LIKES". By doing this, my activity among my friends and family will no longer become public. Now, copy and paste this on your wall. Once I see this posted on your page, I will do the same.
The person that posted this originally is not a tech savvy person. Privacy options are not their forte. And the step by step instructions were far too detailed to be anything they wrote. That's the first clue that something is wrong. My first fear was that someone had hacked their account and published themselves, but why do that when you can make it sound so self protecting that users will just naturally share it and post it to all their friends. Heck, some may even copy and past it into email and send it to everyone on their mailing list even if they don't know they have a Facebook account. Or, like me, they might even post it on the internet on the blog...
My first comment to the person who posted this was "delete me." The next day I was still there and there were no other comments after mine. I decided to investigate a little further.
First off, why would any "friend" post a general posting that says, if you don't do what I'm asking you to do, I will delete you.
The second issue is that if it is about privacy, then a statement like "we cannot change this setting by ourselves" would indicate that this is not privacy.
Lastly is the invitation to share it with your friends, "once I see this posted on your page" I love the ones in email that say, someone will die if you don't share this, or you don't love god if you don't share...
Of course, once these steps are followed, you'd never see any more comments and thus if anyone said don't do it, those that already did wouldn't see it.