Not in my lifetime, but someday, somewhere, some team will figure out how to read your thoughts from the signals emitted by your brain. This is not in the same league as human teleportation—theoretically possible, but in truth fictional. Mind reading is, it seems to me, quite likely.
And, as we know from hard disks and flash memories, to be able to read is to be able to write. Thoughts will be implantable.
Some will applaud the development. After all, it will aid the absent minded, enable the mute to communicate, preempt terrorism and crime, and conceivably aid psychiatry. (It will also cut down on texting and provide as reliable a staple for cartoonists as the desert island and the bed.) Some will, quite rightly, deplore it. It will be the ultimate invasion of privacy.
Game-changing indeed. If we choose to play the game. Until about forty years ago, we lived in the "If it is technically feasible, it will happen" era. Now we are in the "If it is technically feasible, we can choose" era. An important moment was the decision in the United States in 1971 not to develop a supersonic transport. An American SST would hardly have been game-changing, but the decision not to build it was a watershed moment in the history of technology. Of course, since then—if I may offer up my own opinions—we should have said no to the International Space Station but didn't, and we should have said yes to the Superconducting Super Collider but didn't. Our skill in choosing needs refinement.
As what is technically feasible proliferates in its complexity, cost, and impact on humankind, we should more often ask the question, "Should we do it?" Take mind reading. We can probably safely assume that the needed device would have to be located close to the brain being read. That would mean that choice is possible. We could let Mind Reader™, Inc. make and market it. Or we could outlaw it. Or we could hold it as an option for special circumstances (much as we now try to do with wiretapping). What we will not have to do is throw up our hands and say, "Since it can be done, it will be done."
I like being able to keep some of my thoughts to myself, and I hope that my descendants will have the same option.