My family talked me into it, and honestly, I'm kind of sorry I opened a Facebook account. Mine is pretty anonymous, and I just have immediate family and a few cousins as friends.
But the irksome part is, now family sends me stupid messages via Facebook, rather than via email as I prefer. It is OK for staying in touch with family, but I find it more aggravating than not. I'd be tempted to close the account, but I'm sure my family would be aggravated by that. I definitely don't trust Facebook's security.
Anyway, I mostly ignore it these days. And I'm thinking I may not bother to post there anymore. I figure if the family can irk me by sending Facebook messages, I can irk them right back by sending my news as email.
I don't sign in and out of the account much, I have a desktop widget so I can see the feed from the family and a few other places of interest. And/or I check the Android app.