It's interesting to think of this from a security point of view. What data can be exfiltrated? How much signal are we giving off all the time that would leak in

It's interesting to think of this from a security point of view. What data can be exfiltrated? How much signal are we giving off all the time that would leak information on way more of what's going on inside than we realize? If Spectre can use a timing side channel to peer into regions of memory that were not supposed to be accessed, how many more side channels are there in a human body that mostly wasn't designed to conceal anything? (That's not exactly true, we've evolved to hide quietly, many things hunt by smell, women conceal their state of fertility, etc. But technology can access a much lower threshold of signal than anything evolution has had to worry about.) If you listen closely enough, I'd expect we're all open books. Time the exact duration that nerve impulses travel, that blood coagulates, that sweat is produced, that hormones are released, etc. Look at the ratios of chemicals produced by digestion, respiration, locomotion, etc. Technologists are already mining some of this wealth of signal from just filtered speech recordings. There's so much more that could be harnessed (and abused).