"The paper also warned that the FBI had noted domestic activity 'consistent with preparations' for airplane hijackings or other attacks - 'including recent surveillance of federal buildings in New York.'"

From the AP report accompaning the briefing"

"One item in the memo referred to 'recent surveillance of federal buildings in New York." A White House official speaking on condition of anonymity that that was a reference to two Yemeni men the FBI interviewed and concluded were simply tourists taking photographs.'"

Maybe the FBI was wrong and we should just disband them as incompetent.

Are you reading too much into the word hijacking? Remember why the pilots cooperated with the hijackers on 9/11? They had been trained to assume that the hijackers wanted to take hostages and negotiate with someone, so they'd be safer cooperating. How can anyone read this and this alone and assume anything more? Particularly given that the information was uncorroborated as the briefing itself says? How much do you expect the government to do on rumors alone? We had been on alert for nearly six weeks prior to 9/11 with what was then what we considered hightened aiport security. What more would you have done if you were in charge? Honestly?