Philly, Facebook, like the internet in general, has vulnarabilities, which if a person stays up-to-date, and adjusts their personal settings, (and avoid the apps), can be fairly safe. It all depends on HOW one uses Facebook. I have a Facebook page; I got paranoid after following the threads here and deactivated my account, but then decided I needed to stay up-to-date with Stardock, and get information about other things in the world, so reactivated my Facebook account. All of my "friends" are either family, or work colleagues. I use my Facebook page as professionally as possible (I rarely post anything on my wall that is political, religious, or overly-opinionated -- trying to avoid embarrassment in the future or make myself a target).
Good things I've had happen through Facebook: Got back in touch with my best friend from middle school/high school, and discovered she's NOT dead like I thought, and living only 200 miles away, so we're going to get together on the 4th of July and catch up on our lives. Got in touch with a friend I was close to when my children were babies and her children were babies, got to see old pictures of our babies together, and got to see pictures of what those babies look like as full grown adults, shared old times, found out we had even more in common now -- great time reconnecting. Also, found my cousin's Facebook page, learned more about what he does for a living, chatted, shared ideas--now my Mom isn't as judgmental about my life, because cousin Paul approves of it; why my Mom would put more weight into my cousin's opinion of me than she would about taking me at face value, I'll never know, but my family life is more satisfying having made this connection through Facebook.