"Die Gedanken sind frei..." - can someone guess them? A truly dystopian question.

It is been 10 years ago when I looked through some research in that area. Back then it was the problem to get enough good signal. Has the situation changed radically here for non-invasive electrodes or portable detectors?

I understand that the approach would be to turn weak signal, context, and LLM based signal processing into useful human computer interaction. For everything else, I have the feeling we are still in speculative territory.