What if the communication were stored on a digital device, embedded in a person's skull, which they were able to interface their brain with?

That may sound like an unrealistic scenario, but there are already people with medical implants that record digital data, and there has been a case of using Fitbit data to help convict someone:

https://www.nytimes.com/2018/10/03/us/fitbit-murder-arrest.h...