Why can't I take a picture?

One thing that I am very confused about is the fact that people have problems when you take pictures of them in Second Life. I admit that I don't believe that it is normal but that fact that Dr. Essid had to make sure that we knew to ask people if it was OK to take a picture is slightly discouraging. Some of the sights beg to be photographed and I would worry if there was a large group of people there, in which one or two might object. I feel this doesn't reflect real life, because you never have to tell a child, "here's a camera, but you have to ask everyone around you before you use it." That makes no sense! On a side note, I believe the SL term for real life is first life but I refuse to go so far into the Uncanny Valley that I have to specify whether I am talking about Real life or a computer program.

This question sticks with me because I do not know that much of Second Life and I am aware of my ignorance. I do not expect to overcome this in a day or even a month but I would like to know more about the picture taking etiquette. I understand that people have written overwrite codes to establish that they don't look like a newbie every time they take a picture. I can also understand why people wouldn't want to look like they were taking a picture is they were gathering evidence to report to the administrators, but I cannot conceive why people would object to having their picture taken at a random site. I would never object to a picture as I control the avatar and wouldn't do something with it that I wouldn't want captured for eternity through another person's lens.