As far as I understand from the post, as long as one person is your friend on facebook (and perhaps even if you just exchanged messages with), and also has your real name and phone number on their phone and linked those two together - facebook can therefore link this (fake) user to your (real) identity.
I don't think anyone actually does that? Link facebook accounts to contacts in their phone?
I mostly go by a nickname, I haven't yet seen anyone add me to their phone using my real full name - I think only about 10% of the people I know even know my full real name, many just assume my facebook name is my real name. I feel pretty safe.
