"The paper hypothesises that the many opinions found online can expose people to ideas that challenge their world view, make them feel less exceptional and, when opinions are strident or include hateful content, offend them."
This just in - different people have different opinions and world views, exposure to different world views may challenge ones own perceptions and, for the kicker, the world is a big and sometimes ugly place.
That kind of statement, quoted above, smacks of parents home-schooling their children to 'protect' them from incompatible world views. We can't have that - after all, if you are exposed to the the whole gamut of human beliefs and opinions - beliefs and opinions they hold just as strongly as you hold yours - you might just realise that your own world view owes little to any absolute or objective truth or right-ness and much to your upbringing and circumstances.
Keep going down that road and you might learn that the world isn't black-and-white and even, if things go particularly bad, to see the that grey world from other peoples' point of view.
Also - breaking news - if you stand up on a street corner broadcasting your personal ideologies and opinions to the public then some people will disagree and some of those will do so loudly and/or impolitely.
Miley Cyrus has a right to express herself. Everyone else, however, has the right to judge her and the right to express that judgement.
Sure people can be cruel, arrogant, callous, spiteful dicks. But, just like in patents, adding 'on the Internet' doesn't magically make it some new phenomenon.