The Raspberry Pi 2 is an awesome upgrade over previous models, but it also comes with a quirk. It turns out if you try to take a picture of the Pi with a flash, it powers off. The folks over at Raspberry Pi explain exactly what's going on.
Essentially, when you flash the Pi with a xenon flash, the photoelectric effect takes over and knocks some electrons loose. That causes the Pi to crash. It's all rather complicated, but there's good news: This won't damage your Raspberry Pi 2 in the long run, and it's a pretty isolated set of circumstances. Only a bright xenon camera flash or laser pointer will set off the Pi 2, other bright lights won't do any damage. Of course, the easiest fix right now is to use a case or get a small blob of Sugru to cover the components. Head over to the Raspberry Pi site for all the science-y details.
Xenon Death Flash: A Free Physics Lesson [Raspberry Pi]