I'm not sure it should be neither friends nor colleagues. At least as soon as you call it "friends" you create a stigma when it comes to following/unfollowing etc. You can't _unfriend_ someone you meet, even though you might not want to read each single update this person is making.
("People" is a good suggestion. I like "subscriber" for the singular, or something else more neutral than "friend".)

Though of course people could create their own "GNU Facebook language pack"...