According to the Global Terrorism Database and Global Terrorism Index, cited in this article, only a small percentage of terror attacks have been perpetuated by Muslim or Arabic terrorists. Yet, while Muslim/Arab victims are among the most targeted by terror attacks, when Westerners visualize a member of such organizations, they picture an individual with Muslim/Arab/Islamic ethnicity. This story was also picked up by MintPress News.
A Department of Homeland Security Emeritus Center of Excellence led by the University of Maryland