Maybe "sole ownership" is a better way to say it. If I have my toothbrush, you don't. My ownership necessarily means that you can't possess it without my permis

Maybe "sole ownership" is a better way to say it. If I have my toothbrush, you don't. My ownership necessarily means that you can't possess it without my permission. Also, if you take it, you can be made to give it back. Data isn't that clear-cut. Your knowing my name and address doesn't take that knowledge from me. It's not obvious that you know it, nor how to make you "give back" that knowledge. So it's less clear what my ownership of that data would mean. Unlike possessions, there's some fuzzy continuum from "clearly it's fine for someone to look at me when I walk past and know what I look like" to "clearly it's not fine for someone to track my every move and sell that knowledge for profit without my consent."