I'm not clear on exactly how and what sources this tool uses to achieve this madness, but the fact that it was achieved is quite telling as to how lost this game is.
I really cannot fathom how anyone, and particularly anyone in IT, has not understood and accepted the concept that "if you do it online, it's public" is true for a very, very long time now. Unless extraordinary measures are taken to ensure privacy, which are never the case with most web activity, it's on public view for those who want to devise the methods to view it.
It's the cyber-extension of public records, which were always public but where privacy was largely maintained because there were no tools other than some human's eyes to review them. Now we have electronic methods to constantly pore over not only real public records, as conventionally construed, but internet activity.
ISPs, Google, Microsoft, Amazon, and the list goes on and on have been using electronic surveillance (for their own purposes related to making money) for decades now, and the degree and refinement in that surveillance has been on an exponential curve.
What really creeps me out, though, and I wish I could locate the NPR discussion I originally heard about this during, is that there has existed technology, for years, that can extrapolate what any random "you" are likely do to in any random decision making scenario with stunning accuracy with very few data points obtained entirely legally and from your online activity (mostly). It was really shocking how accurate those predictions could be, about entirely different decisions, based on data points collected that would appear to any rational human being to be entirely disjoint from the thing being predicted.
Nothing, absolutely nothing, has been private in the ways even my parents, let alone my grandparents, understood that word for at least half of my life now (and I'm 61).