It's a rare occurrence for a black bear to attack a human. They are not looking for confrontation but they are like people, most will run but there are a few that have nasty personalities, you don't know which one your up against. A three hundred lb black bear could destroy any human, some can get up to 500 and even 700lb A bunch of hikers were attacked in B.C. by a five hundred pounder, killed two of them just a few years ago.
An old gym friend used to work for the local Humane Society. He said if the bears travel down into the residential neighborhoods (searching for trashcan scraps, of course), they had no choice but to destroy them.
Initially, they'd tranquillize the animal and drive it hundreds of miles from where it was found and relocate it back into the wild. But the f'n bear would keep finding its way back to the exact same trashcan. Sounds unbelievable, but the guy wasn't one to exaggerate. Eventually figured they had to euthanize. That's how they handle it in Pasadena, anyway.
