Skin
"People could look back in 100 years and identify the coronavirus epidemic as the moment when a new regime of surveillance took over, especially surveillance under the skin which I think is maybe the most important development of the 21st Century, is this ability to hack human beings."
-Yuval Noah Harari
Source:
https://www.bbc.com/news/av/technology-52441339
And who is Yuval Noah Harari?