O.S. Sie sind der mann.
What a superb explanation. I read it carefully twice, I now understand v6 addressing. I did know the history of it was due to exhaustion of v4, but beyond that I had no clue, I didn't know MAC addresses were involved (usually anyway), and I can see why that would scare people. So it should too, as you said, it's a golden ticket for targeted advertisers. Brilliant write up, thank you so much.
I will turn ipv6 back on