Please. In the year 2001, it's been documented that Atta spent significant time in at least fifteen different cities at one point or another: The Venice, FL area; the Fort Lauderdale, FL area; the northwest Georgia area; Virginia Beach, VA; Paterson, NJ; Las Vegas, NV; Prague, Czech Republic; Zurich, Switzerland; at least three different cities in Spain; Toronto, Canada; Hamburg, Germany; Laurel, MD; and finally Boston, MA, and Portland, ME.
Using this person's three-day-window, Atta probably "intersected" with several hundred million people in calendar 2001.
This is just idiocy.