Ya, Yosemite Bears are smart!!!
The scary thing, after talking to a local Yosemite Ranger last time I was there, is that the bears are figuring out how to open the bear buckets, steal backpacks, open car doors, etc...those bears are smart.
Perhaps it is habituation, perhaps it's the tourist feeding them, or perhaps, the most likely case is that the bears are in an area where the influx of people visiting is high; b/c of the constant flux of people milling in an out of Yosemite, bears (being all ninja like) are able to watch people perform the same motions day in and day out eg. open car doors to get to food, open backpacks to get to food, open bear buckets to get to food. With all this exposure it seems like the bears pick a thing or two.
Monkey see, Monkey do?