I always ask if people dont mind having their photo taken, just as courtesy cos I know it can sometimes be intrusive or people are just self concious.
With phones these days everyone seems to be taking pictures, but still I think it can be annoying esp if you are not used to it...and people didnt seem to learn from princess dianas life I think that was a modern tragedy. She was the most photographed woman in the world yet very unhappy. She would say she was smiling in all her photos and wonder why, because she might smile but her eyes were sad...
But she was also one of the people who said they liked the press, like having their picture taken, and then privately she would tell other people she hated them!
What I reckon she could have done was buy a camera of her own and take it on her royal visits, and walk around taking pictures and selfies with people instead of complaining about the paparazzi. Turn the tables. Can you imagine, thousands of people turn out to see the princess, but instead shes the one taking pics of all the crowds to put in her scrapbooks.