That's some Matrix stuff right there. I think it really depends on what you intend to do with such an advanced VR technology. I wouldn't call it unethical if you use an immersive technology to gain experiences. As long as the participant knows it's fake, it seems ethical. To experience VR is to basically lie to yourself. You lie to your brain That doesn't mean it's necessarily bad: in a game of poker, you're lied to all the time. But that's because it is a part of the game, and everyone knows it happens. When you willingly enter a virtual reality, you know that it is just that: virtual, fake, never truly real. It gets unethical if someone is put into virtual reality without them knowing. When reality and virtual worlds are mixed up, when the line is blurred.