Great thread..
Couple of thoughts...
I was thinking the same thing when I saw the photo, hoping that the person taking it wasn't the only other person around and that others were working on spooking the bear, glad that was the case!
On bears, I watched a great documentary regarding bear attacks and the researchers concluded that black bears were less predictable than grizzlies, and that attack:fatality ratios were stacked higher for black bears, this isn't total fatalities, but ratio of attacks that proved fatal...another way to think of it was that they attacked less but more often those attacks were fatal. Driving the attacks was less often protection of cubs and more often the need for a big meal; eg, low body weight late in the season.
There was one attack in particular that took place up in Canada I think around New Brunswick (not sure, if anyone knows this please correct me) where a couple took a canoe out to an island and they put two bags of groceries on a picnic table in thier camp, which was right on the shore. They were both killed that night by a black bear. Two days later they were reported missing and rangers went out to thier camp site. From off shore in thier boat, they oberved the bear feeding on them...the kicker is that the bear never touched the bags of groceries.
On desensitization; YUP. This is a big problem, especially in areas of sprawl. Predators see people, people do nothing, predators conclude people are harmless. I have an airblaster and have used it when I've seen coyotes in my back meadow. The coyotes cruise the wooded perimeter, but will rarely step foot in the meadow and run like hell when they see me and the dogs. I've been here now four years, and I rarely see them since I blasted them.
Anohter "Unadogger's Picks" book plug:
"The Beast in the Garden" by David Baron. My friends who live in Nederland Colorado turned me onto this book when I was staying in their cabin (consider it the worst campfire scary story anyone could ever tell you, right before you went to bed). They happen to live right along established cougar routes. One cougar in their neighborhood got so habituated that he developed a taste for dogs and proceeded to eat five pets. He was ultimately shot. But this is a great book about urban predators, the struggle between open space and sprawl, and even where greenies can go wrong in the game of wildlife management.