I'm sure you're at least partially right. Data clones would never be accurate though, since the computers could only aggregate surface behavior, such as online actions, but not the reasoning behind them, or the chaos aspects of life that constantly affect how people act. In example, people with painful injuries like a broken foot are often either quick to anger, or slow with painkillers, but the computer reconstructing the personality would have little to no idea about these background factors, and would always paint the persona inaccurately. Makes you think about this whole internet culture of trying to find someone's worst comment or action of all time, and then judging who they are as a person by that. I think it's at least possible that people are a bit deeper than their online comments from any isolated day. AI is very much about weighting, or ascribing relative importance to many factors being analyzed. Which comments were offhand, which were jokes, which were windows into their soul? If you can't know for sure, the AI probably can't either.
My Amazon Shopping history would not really tell you much about me. I buy more hard drives than most people, that's it. I can hear an AI tearfully eulogizing me now. "Nate was many things, a husband, an inventor, an artist, but above all, he was a purchaser of 2.1 standard HDMI cables"