Remember to activate your brake light while slowing down

On the way home today, I saw a fellow motorcycle enthusiast almost get rear ended 4 times because they only engine braked, and hit the brakes ONLY when they came to a stop. On the last one they got visibly mad at the car driver. Of course the driver should visibly notice them slowing down, but let's help out the murderous cagers who ALREADY want to kill us by activating that brake light.