It was always just a matter of time before bears were found to outsmart "bear proof" food containers. There have been claims of breached food containers for a while now, but recently the New York Times ran an article about a particular black bear who has bested the Bear Vault 500.
The surprising thing is that the bear has not just overpowered the container and ripped it apart. She has instead systematically learned how to undo the locking mechanism to open the vault and get the food out. For anyone who has ever been frustrated by a "childproof" container, you know what an accomplishment this can be!
Bear canisters have become the preferred method of storing food in the Adirondaks in recent years because the clever black bears had figured out that food bangs hung from trees could be accessed by finding the rope and chewing or tearing it down. Now that one bear has figured out the canister, it's only a matter of time before others learn the trick too!
Other types of canister are available which require a screwdriver or a coin to open the locking mechanism, and bears have so far not found any way to get through those ones. (Although I can almost picture one rummaging around the campsite looking for loose change!) So if you are camping in bear country, that might be the way to go for now.
If you're determined to avoid bear encounters altogether you're left with a few choices. First, you could camp during the winter while the bears are hibernating. Second, you could join me down in New Zealand where there aren't any bears in the woods. Or third, you could turn your camping trip into a major detox and not bring any food! (OK, I don't recommend that one.)
Anyway, let this be a lesson to anyone who thought that bears were just big brutes without much intelligence. They are not to be underestimated - and they can climb trees, swim, and outrun you!