As I understand it, Polar bears are the largest land predator and will track and kill humans for food. Understandable since the bears are trying to survive in a pretty bleak environment with food not that easy to come by.
But once a wild animal gets a taste for human, the only option is killing it.
When I lived in Alaska, a local friend of mine told me that some Alaskans can get a permit to hunt Polar Bears. When I asked him how do you hunt Polar Bears, he told me that it was really easy because the Polar Bear is the only bear that actively hunts humans. All you have to do is show up in their territory and they will come to you. Yikes! I like varmint hunting but will pass on hunting something that could easily have me for dinner.