Some museums do severely prohibit photo taking in certain areas because of the light damage to delicate objects, but I can’t imagine how the cost of security would escalate if they had to monitor and detain all photographers… In regards to etiquette, I agree—photograph taking can become really rude. I was taught museum etiquette when I was young- don’t touch, don’t jostle people, be aware of your noise level… looks like a lot of museum-goers today need to hear from my mama on this one!