As your grandmother told you, it's easier to catch flies with honey than with vinegar. (Okay, it's more likely that her grandmother told her; I'm an old man.)
That's sometimes a good rule when you're writing letters to the editor. When the paper publishes a story which is egregiously wrong, we write; and we should write. But we also whould write to compliment the paper when they print a story which is right-on. Always mention the name on the byline when it's a good story; reporters live for getting credit, and credit the next day is icing on the cake.
Remember that the longer a story is discussed, the better for the side which benefits from the story. You don't have to say anything profound about NSA eavesdropping; just mentioning it will prolong people's irritation at the administration.