Why everybody discussing this? It looks obvious that any US citizen at any moment can be reached by FBI with a call for information; there is no countermeasure

Why everybody discussing this? It looks obvious that any US citizen at any moment can be reached by FBI with a call for information; there is no countermeasure against it; since Patriot Act was enacted, you'll never know who gave any piece of information to FBI. And now, somehow, "according to anonymous source", BusinessInsider highlights a very specific pro-Trump person and trying to convince readers of something. But what exactly happened?