Last Updated Oct 15, 2012 4:49 PM EDT
The judge told each man that the trial would go on without them if they were to somehow escape, a notion that prompted a smile of disbelief from Binalshibh. "I'm escaping from custody?" he said in English.
The same question prompted some sarcasm from Ali Abd al-Aziz Ali, a Pakistani citizen accused of funneling money to the hijackers. "I'll make sure to leave some notes," he said in English.
The focus of the week's hearings include broad security rules for the prisoners, including measures to prevent the accused from publicly revealing what happened to them in the CIA prisons.
Prosecutors have asked the judge to approve what is known as a protective order intended to prevent the release of classified information during trial.
Lawyers for the defendants say the rules, as proposed, will hobble their defense. The American Civil Liberties Union, which has filed a separate challenge, says the restrictions are overly broad and would improperly keep the public from hearing the men speak about their captivity.
Protective orders are standard in civilian and military trials to set rules for handling evidence. Military prosecutors argued that the Sept. 11 trial requires additional security because the defendants have personal knowledge of classified information about interrogation techniques and knowledge about which other countries provided assistance in their capture.
The U.S. government has acknowledged that before the defendants were taken to Guantanamo in September 2006 they were subjected to "enhanced interrogation techniques" which in some case included the simulated drowning method known as waterboarding.
Defense attorneys say the treatment will be used in their defense, but the proposed order limits their ability to make that case in court.
The judge's approval of the protective order, which may not happen this week, must occur before the Sept. 11 case can move forward. Defense lawyers cannot begin to review classified evidence against their clients until it is in place.
Mohammed and his four co-defendants are being prosecuted in a special military tribunal for wartime offenses known as a military commission. They were arraigned May 5 on charges that include terrorism, conspiracy and 2,976 counts of murder in violation of the law of war, one count for each known victim of the Sept. 11 attacks at the time the charges were filed.
Mohammed, a Pakistani citizen who grew up in Kuwait and attended college in North Carolina, has told military officials that he planned the Sept. 11 attacks "from A to Z" and was involved in about 30 other terrorist plots. He has said, among other things, that he personally beheaded Wall Street Journal reporter Daniel Pearl. In addition to Ali and Binalshibh, the other defendants are Walid bin Attash; and Mustafa Ahmad al-Hawsawi.