Apparently some folks just don't understand that metal whirling at high-rpms driven by a gas engine is in fact a deadly weapon. According to News10.net:
A 67-year-old Stockton man used his chain saw to frighten off a man who not only tried to rob him, but pulled the trigger of a gun during the crime. It happened Sunday morning behind the Safeway Store in the Country Club neighborhood of Stockton. Jerry West was doing tree maintenance after one of the trees behind the store fell during heavy winds. That's when he was approached by a man with a gun.
Mr. West is lucky the thug's gun was defective and the thug is lucky Mr. West wasn't younger.