Show me your search history, apps, emails, and messages and I can tell you exactly the person you are. Throw all that data into an algorithm and BigTech can tell you what kind of person you are by feeding you back your own data with a twist.
No brain chip required. Everything we think (or don't think) is manifested through our phones out to Silicon Valley and back to us in their package.
How much of your behavior has been altered because your phone suggested a video or Google scrubbed results that you would have appreciated more than what they fed you?