facebook dead

When a person hasn't accessed his facebook account for a long period of time and doesn't intend to do so for another long period of time, the person is said to be facebook dead.

If facebook death is caused to due the actual death of the person, you just call it 'Dead'.

Often people who have a vibrant social life outside the internet are the ones who are facebook dead.
It is an EXTREMELY rare condition.

Steve: Hey, why is John never online on facebook?
Rick: 'Cos he's facebook dead, man!
Steve: Ah, no, look, there he is!
Rick: NOOOOOO, run, he's a facebook zombie now!!!