Niall wanted some way to cash out on his vast knowledge about history, and decided to go after the current hype, facebook. He's not actually worried, he's just following the current public anxiety, and gets to promote his book in the process (nothing necessarily wrong with that, but it's not real fear, and it creates a fear bubble). I'm just making this up, but that's what it feels like based on listening to his interviews (and by reading his most recent book, which feels super rushed and/or like not a lot of love went into it).