[granular]

Not only that (parents complaining to teachers), it gets worse. Some problem parents actually go straight to the principal to complain about the teacher -- based only on what their child told them ("But mom, Mrs. So-and-so picks on me! She told us X wouldn't be on the test, but it was! And she's unfair!"). This is without ever even contacting the teacher (this tactic is often coupled with "but I tried to contact Mr. So-and-so but he never got back to me").

Other parents think they'll go "straight to the top" and complain directly to the superintendent of schools in their town. When time comes to renew jobs for non-tenured teachers, I've heard tales of non-renewal (for the next school year) just because of a couple noisy parents.