You may be right, but I've never seen it happen. I have over 600 "friends", many of which I've conversed with online, but none of whom have commented, posted,

You may be right, but I've never seen it happen. I have over 600 "friends", many of which I've conversed with online, but none of whom have commented, posted, or tagged me on -anything-. The exception being the people whom I've met in person.