Honesty?

I've often wondered how honest I can be with people? Facebook is a fertile test ground for that but I'd hate to come off as the judgmental a-hole who has everything to say to everyone. I have 1800+ "friends" on Facebook....a small group of them real live, or virtual friends...and the rest just people who either hit or accepted the "add as friend" button. I wonder, if I went totally honest today on the stuff I see posted, how many of all of these people would go away?