How many times do we see riots and crowds and think 'mob mentality' when the <a href="http://aeon.co/magazine/living-together/crowds-show-us-working-together-at-our-best/">truth is exactly the opposite</a>. Police and crowd management can go a long way to keep crowds safe.
"...people in crowds behave not with mindlessness or madness, but by co-operating with those around them. They do not lose their heads but instead act with full rational intent. "