During the flight, the men again acted suspiciously. Several of the men changed seats, congregated in the aisles, and arose when the fasten seat belt sign was turned on; one passenger moved quickly up the aisle toward the cockpit and, at the last moment, entered the first class lavatory. The passenger remained in the lavatory for about 20 minutes. Several of the men spent excessive time in the lavatories. Another man carried a large McDonald's restaurant bag into a lavatory and made a thumbs-up signal to another man upon returning to his seat.