Except a whole bunch of people in the world AREN'T civilized, and ARE nasty, despicable individuals. You add the anonymity of the internet to this, and that's magnified, and brings out the worst even in people that are quite normal. Hell, some people might not even be despicable human beings. They just get a kick out of trolling people...
The Karlssons are adults. This should be common knowledge to them.
Antiquated take? It's called logic. Using social media is a choice. Your social media being PUBLIC TO EVERYONE, is another choice. Nobody needs to have social media, let alone public social media. There's a very simple solution to these things. Make your social media private. Share things with people who you ...actually know(BUT HOW WILL I GET THOUSANDS OF LIKES THIS WAY?!?!). People who you actually, you know, interact with...in real life. Or, if you choose not to do that, you must accept that people are cruel, nasty, despicable, lowlife scum, that WILL say things to you just because they can. And you better have the mindset to be able to deal with it.
My children are not allowed to have public social media profiles until they are adults. Period. There is absolutely no reason to share your life with complete strangers, most of whom don't give a flying **** about you, and WILL say nasty things, just because they can. Educating and protecting your kids from social media is just as important as educating and protecting them from every other danger in life. We teach kids "don't talk to strangers" but then we let kids talk to strangers on the internet???? Where's the logic?