During the Bill Cowher years as Steelers coach, he had one of his staffers peruse the newspapers, clip stories they felt were relative and, yes, post them on a bulletin board.
It was just as you can imagine. Usually it was a piece containing demeaning information about the Steelers, or providing other such psychological ammunition relative to an upcoming opponent. It often was highlighted in yellow and greeted the players as they walked into their locker room.
So, yes, Virginia, coaches do believe in bulletin board material. Whether it actually works is another matter, but you can be assured that if there is a bulletin board in Foxborough, Mass.