Whenever I see a vehicle with it's hazards on I assume there about to pull a maneuver that could be mistaken for the opening stages of a terror attack.
I think I heard David Mitchell talking about how hazard lights have gradually changed from 'look out, there's a problem with my car/something ahead and it's about to become a hazard' to 'look out, I'm about to do something incredibly dangerous with my car'.
Van parked across the whole northbound cycle lane at Ludgate Circus. Had his hazards on though so I guess it's ok.