These fitness trackers aren't just "fitness" trackers. They can tell if you're depressed. They can tell when you're sick. They can tell when you're having sex.

These fitness trackers aren't just "fitness" trackers. They can tell if you're depressed. They can tell when you're sick. They can tell when you're having sex. Some have gyros that augment the heart rate sensor, so they basically know what you're doing with your hands at all times. Even ones without GPS can use Bluetooth to figure out where you are. And of course they upload it all to the internet to be stored and profiled for all time. We all know it's technically possible to have end-to-end encryption for the data, and so we all know the reason that they don't do it: to mine your data and create psychological profiles. Today it's just for ads, but tomorrow it could be for health insurance, credit scores, life insurance, some kind of "homeland security" or any number of things.