Among other topics in social psychology, my husband studies uncivil behavior and the factors that lead people in the street to express disagreement with, and even attempt to prevent, such behavior.  This intervention by a by-stander is usually called “Social Control.”  Recently it is also called “Civil Courage.”  This second label recalls the fact that such intervention can actually be dangerous (which is one reason it does not always occur).  Last year a man who stepped in when a small group of thugs stole a cell phone from another kid on an U-Bahn in Munich was murdered by those very thugs at the next U-Bahn stop.  Uncivil behaviors are not always as dramatic as theft, and include tagging, littering, cutting in line and … failing to pick up poop after ones best friend.  By the way, the term for dog poop in French is déjections canines.  Love it.