The NIE from several years ago that assessed the trends in global terrorism, identified "four underlying factors that are fueling the spread of the jihadist movement:
(1)Entrenched grievances, such as corruption, injustice, and fear of Western domination, leading to anger, humiliation, and a sense of powerlessness;
(2) the Iraq “jihad;”
(3) the slow pace of real and sustained economic, social, and political reforms in many Muslim majority nations; and
(4) pervasive anti-US sentiment among most Muslims
http://www.dni.gov/press_releases/De..._Judgments.pdf
IMO, those words, signs and acts further fuel that pervasive anti-US sentiment that already exists, particularly among the young.