He's not wrong. The internet is an enormous threat to existing societal norms, power structures, and even governments, there's no doubt about that. However, he is wrong in believing implicitly that the existing status quo should be defended. The internet has the potential to empower disruption, and in it's short history it has proven to excel primarily at disintermediation. However, for people who support the ideals of liberty, of governments that are consensual and responsive to their people these trends are not alarming, indeed they are salutary. But for rulers who rely on oppression, propaganda, etc. these things are scary.
Hopefully, people who have educated themselves via history, philosophy, political science, etc. and look for the well being of a majority of the population.
Who's to decide? You? You'll have a bashed-in head soon enough; people whose heads no longer contain neural matter don't have opinions. Does your necessarily brief opposition really count?
I somehow don't think he was referring to Facebook addiction and social alienation resulting from "virtual friends", which is about the only time I would agree with someone who says social media is "hurting society".
Its an interesting question, but I would have as much concern for someone who conducted their social life primarily via hand written letters as I would someone who spends 10 hours a day on Facebook.