Have a look at this CBC story about two silver-backed Grizzly bears who decided to carry out a little terrorist attack. I lived in Atlin with my family when we first moved to Canada in 1969. This is really unusual behaviour for bears. I remember taking a canoe out with my girlfriend on the Atlin Lake for an overnight on the beach. No one around for miles, it was about as isolated as you can get. We had sleeping bags, set up a campfire on a pebble beach, and watched the northern lights. Sometime during the night, we heard a snuffling and crunching on the stones. She felt something nose around at the bottom of her sleeping bag. Then it was quiet. We never were sure what it was. The Patron Saint of Stupid 11-Year-Olds must have been watching over us.