There are bubbles, you are obviously in one if you do not know any privacy concerned under 25. I know 15 year olds who are extreme privacy freaks, then I care about it so it might be easier to find those people. I do find that it is the people that I think are least likely are the one who are the most extreme.
You make a good point. I know a couple in there late 20s with kids who are pretty apathetic about their own privacy but who refuse to let Google or iCloud sync photos of their kids.
I'm pretty sure they care who takes pictures or videos of them.
Try going on a train and taking pictures of a young woman or man.
The only difference is these are less noticeable.
On the other hand, EVERY young person in my circle (my kids and their friends) is insanely privacy aware. All of that means ... we're not part of the young people anymore?