>>982419 (OP)
>Two of the three subjects are "Senders" whose brain signals are decoded using real-time EEG data analysis to extract decisions about whether to rotate a block in a Tetris-like game before it is dropped to fill a line.
Let's take a pause right here. EEG data is dogshit and offers near zero ability to "read your thoughts". At best, you can use EEG read-outs to make binary decisions (which is what is happening here). Imagine tens of millions of wires all firing in a big tangle, then embed those wires in fat and blood vessels, then cover that fat with a thick membrane, then cover that in a cm of bone, then cover that with a membrane containing more wires and blood vessels. Now put a handful of electrodes on the outer membrane and try to guess what the wires inside are doing. That's EEG. All you can do is try your best to filter out physiological and environmental "noise", then Fourier transform the remaining signal, bin the frequencies into 4 or 5 bands, and then write code that does different things depending on the frequency bin with the greatest power. What you get is a computer program that says "yes" or "no" depending on the EEG read-out, with slightly-above-chance accuracy. This is not technology to be afraid of.
>The Senders' decisions are transmitted via the Internet to the brain of a third subject, the "Receiver," who cannot see the game screen. The decisions are delivered to the Receiver's brain via magnetic stimulation of the occipital cortex.
I'm assuming they mean transcranial magnetic stimulation (TMS), which is another ham-fisted tool with near zero utility. Pulsing TMS on the occiptal cortex causes the perception of a quick flash of a little white light. You could pulse one side of the cortex versus the other to bias the general part of the visual field you elicit the phosphene in, but, again, it has the precision of a bulldozer. At best, you could elicit maybe 4 unique phosphenes, given how small the visual cortex is and how indiscriminate TMS is.
TL:DR, these people are coming for you and they do want to read/write to your brain but these technologies certainly will not be the tools by which it will be accomplished and you'll all most likely be dead before the tools are even conceived of, let alone developed.