Polar Bears do Stalk Humans and sometimes make a meal of them
A number of people have been taken by polar bears over the years.
Steffanson in one of his books recounts how when he made the mistake of stalking a polar bear from upwind, the bear rounded about and stalked him as he discovered at the last moment when the bear unwisely let out audible gloat before the lunge -- not smart when your prey is armed.
Other arctic explorers at the turn of the last century found polar bears easy hunting. They let the bear know of their presence and waited for it to come into range of what the bear thought was an easy meal.