Since 1972 Gallup has been asking people in the US:
In general, how much trust and confidence do you have in the mass media — such as newspapers, T.V. and radio — when it comes to reporting the news fully, accurately, and fairly — a great deal, a fair amount, not very much, or none at all?
So net trust has gone from around +40% to -40%. Only one third of the population has a great deal or a fair amount of trust in the media and over two thirds say they have not very or no trust.