YouTube is removing videos that incite calls to holy war made by the American-born Muslim cleric Anwar al-Awlaki.
The Google-owned company made the decision after receiving pressure from American and British officials.
A spokeswoman for the video sharing site said the videos violate guidelines which prohibit "incitement to commit violent acts."
Al-Awlaki, a citizen of both Yemen and the United States, has appeared in more than 700 YouTube videos that have received more than 3 million views.
Al-Awlaki is the mastermind behind a series of attempted attacks against the West, and reportedly met with the 9/11 hijackers prior to their attacks.