I'm a bit more cynical and was thinking of the military using it for interrogation, or worse police getting a warrant to put a hat on you that pulls the info.

MIT already has a device that scrapes your internal monolog by using sympathetic reflexes in the throat. Technologically speaking, the requirement for an implant is a current limitation that will be overcome.

So while legally questions about use are somewhat ambiguous, typically the solutions don't get resolved until someone decides to abuse it.

Probably not. Probably can configure a button so it will be push to talk or you can mute yourself. Then you can say "Sorry guys I forgot I was muted" in real life