Since 9/11 and this being a major public event with runners from around the world, it's reasonable to see the use of such dogs or even drills, no?
Or maybe there was a report of terror activity. Of course anything else could also be and we'd never be told about it.
Bill Belichick learned to film signals of opponents from the former Chiefs, and Charger's coach Schottenheimer. Others like Edwards, Johnson and Cowher did too. They learned from the CHEATS and CHEATERS who still couldn't win.