No 2x4s needed or warranted! It's healthy I think to get to the point where you don't feel their karma or life is your business. Or vice versa.
And FB? Well, that just sounds like a boundary to me. You're saying I don't want this person's life showing up in mine, whatever the route. If you're not a big FB user, you could always take a step further and decide to close your account. Email the people you want to stay in touch with. You can always start a new one down the line if it suits you. But there was life before FB!
Me: 53 H:38 T:20 M:14 BD ILYB etc 10/15, H diagnosed severe depression S 1/16 PA 4/16 H filed 1/17