I don't agree with Armano's theory of decreasing trust in people as the result of overall decrease of trust in media, the correlation doesn't imply the causation. Following Armano's deduction, we could easily come to the conclusion that we are on the way to slow social disaster of mistrust and alienation along the growth of social media. This is oversimplifying of human relations built on trust. Trust is essential to human relations and is fundamental for social interaction and their development. The question lies in how far circles of trust stretch.
"Trust surveys" suffer from the lack of understanding of what people define as friends/peers. Those surveys deliver mere numbers without any understandings. Facts.
As I wrote two days ago, the main culprit here are "friends" and our language. We should maybe look at the decreasing trust in friends / peers as the result of the devaluation of friendship caused by media as Facebook. We have experienced rapid growth of our circle of friends with people who were in fact strangers to us.