Picture a beach and brilliant sunshine.
A man steps on a jellyfish. The pain is excruciating. And so a posse is formed. The beach is combed. Every nook and cranny is searched. Who would be the first to find the assailant? The man, having been sequestered to a quiet spot in the shade, recuperates from the sharp pain.
Even the starfish and sand crabs join in the hunt, in support of their brethren. Finally, the nasty perpetrator is found under a blue umbrella, and the vigilante group of jellyfish lets loose on the man for having injured one of their own.