The smartest black bears are in Yosemite National Park.
A buddy and I had flopped our sleeping bags down in Little Yosemite Valley. I think we had covered 50 miles in two days of trail, so we were dead tired as we saw this unfold. Some other backpackers had erected a dome tent about 100 feet away, but they were stupid. They didn't have any bear canister (as required), so they took their food bag into the tent with them for the night. After a half-hour of quiet, a black bear came sniffing around. It came right up to the tent, and the people inside became scared. Finally, the three people came running out of the tent to harrass the bear away. The bear ran and the people chased. After about two seconds, a second bear appeared and ducked into the tent to grab the food bag. Nobody had even known that the second bear was around. The food bag was taken, the bears got away, and the people went hungry. It was one of the best-coordinated bear attacks that I had ever witnessed.