Aurora, Colorado: terrorism.
Newtown, Connecticut: terrorism.
Chicago, Illinois: terrorism.
Holbrook, Idaho: terrorism.
London, England: terrorism.
Belfast, Northern Ireland: terrorism.
Baghdad, Iraq: terrorism.
Columbine High School, Colorado: terrorism.
Mombai, India: terrorism.
Boston, Massachusetts: terrorism.

ANY violent act is an act of terrorism. Some are larger in scale than others. The difference between a drive-by shooting and a car bomb exploding in a busy shopping district is only one of size.