There are people who consider that a choke chain is rather inhumane. They prefer using the regular flat collar instead. However this is a rather mistaken point of view.
A choke chain works on a jerk – release motion and distributes pressure equally around the neck region. On the other hand a collar concentrates pressure only on one part of the neck on the side opposite the leash.
So if a flat collar is jerked from above, the entire pressure is focused on the windpipe, which causes a strangulating sensation for the dog. Thus the choke chain is a better alternative.