By all accounts, the crowd that gathered outside the temporary quarters of the Roman governor in Jerusalem on a Friday morning 2,000 years ago whipped itself, or was whipped by skilled political operatives, into an angry frenzy. The issue was what to do with a Galilean peasant who had run afoul of the carefully structured arrangement between the authorities of the occupied people and the greater authority of Rome, as represented by its appointed governor. The crowd became a mob that played a decisive role in the execution of a man innocent of wrongdoing.
Crowds can become dangerous mobs. The people in them can be swept up in anger and rage and may say and do things they would never do on their own.