There's a 3rd category: non-fiction that doesn't necessarily require diagrams. For this category, ebooks are great in the sense that I can add highlighting and

There's a 3rd category: non-fiction that doesn't necessarily require diagrams. For this category, ebooks are great in the sense that I can add highlighting and notes very easily. For me this is the largest category of books and so DRM scares me. It also scares me that the highlights and notes are not owned by me. I wonder if I can somehow retrieve all of them?