Several controversial videotapes recorded by Osama bin Laden were made public after the September 11 attacks on the United States. The Bush administration has cautioned U.S.-based media against airing "prepared propaganda tapes" from bin Laden. Administration officials suggest the recordings, provided by bin Laden to the Al-Jazeera network, might contain coded messages to so-called terrorist "sleeper cells." U.S. officials are balancing their concern with for protecting intelligence sources with the goal of building the public case against bin Laden. Click on the tabs below for a chronology of bin Laden's messages.