 If you assume that essentially every imaginable piece of data about what you're doing online is being recorded somewhere, you will more often than not be right, at least for some segment of the sites you're looking at, and it's probably being tracked by more entities than you would guess. The default, in a sense, has changed. For most of human history, tracking and recording details about any event was an extra step that had to be taken. It was abnormal. Almost everything you did left no permanent, structured, centralized record of what you were doing, your conversations, what you were reading. Data storage costs have plummeted. We sort of hit the point where storing is, in a sense, as cheap as throwing away.