[synu]

Ok but then they wouldn't have been lost by deleting the Facebook, the person could just get back in touch. But they seem to believe it would be weird (psychotic even?) if they did, which to me points to them not being actual friendships.

[OJFord]

I think there is a difference between 'liking' an old friend's stuff, who you're no longer in actual contact with (not talking or meeting or anything), and kind of re-instating contact by 'adding friend' - even if you only intend to occasionally 'like' stuff in the same way as above, they don't know that after all.