Think about it this way: a little sugar, salt and fat isn't harmful. In fact you need salt and fat as part of your diet to be healthy, and sugar was a rare treat - that's why they taste good. But if companies start adding more and more of these things to food, such that the consumers start to forget what real food tastes like, and then start making foods that are nearly all sugar and fat, well that is very bad for your health. That's what social media is. It's food without nutrients, and only the most shallow form of human contact.