My Facebook-friend-acceptance policy is this.
Actually more restricted than that. If I don't share my personal detail with you in real life, I don't want to share it with you on Facebook.
The Facebook data team recently published this study which basically tells that if you want to receive interesting diverse news from your social network you should add people you hardly talk to. People with whom we have strong ties are similar minded, so they share things that we'd have shared. If you social network only contains similar minded people it'd become an "echo chamber." The more diverse your network is the more diverse and novel information you'd get from it.
I find the study very interesting. People with weak ties are good for getting interesting information, but if I have too many of them then I'd have to add extra privacy settings on my photo albums and status updates or be extra cautious about things I share. I'm not sure if people use facebook for getting news, it's an added benefit. News or no news, with my friends literally staying all over the world, I'd use Facebook anyway.