Here is the video of the last speech delivered by Imran Yusufzai, Deputy Spokesman of Hizb ut tahrir  in Pakistan, before his abduction on 12 July 2011 CE. His speech was at the Day of the Fall of the Khilafah "Caliphate", 28 Rajab, seminar in Islamabad. His whereabouts remain unknown.

http://www.youtube.com/watch?v=Q0kaVdU-BC0

http://www.youtube.com/watch?v=hI23Y4xa5a8&feature=related

http://www.youtube.com/watch?v=BVqMMyD_Eis