Though the photos aren't very good, I'd say that those are Racers. "Back in the day" in some older literature I'd occassionally read about Racers attacking people. Carl Kauffled relates and incident where this happened in his book "Snakes and Snake Hunting." (1957)

Apparently Racers have territories that they will defend. This probably doesn't happen very much anymore because Racer populations seemed to have declined.

Tim