Important videos:
1. Ayman Al-Zawahiri refers to an act of terrorism as jihad:
http://www.youtube.com/watch?v=1kqpZGBOKZQ&feature=related
2. Ayman Al-Zawahiri justifies killing of ordinary citizens:
3. Imam Anjem Choudhry (Islam4UK), justifies killing of Muslims:
part1: http://www.youtube.com/watch?v=ko0qQJMN_dk&feature=related
part2: http://www.youtube.com/watch?feature=endscreen&NR=1&v=D1UFD2g3o6A