But the invention of brain-computer interfaces, including implants and headsets, has raised concerns that so-called Big Tech could some day be able to read people’s thoughts and use information gleaned from brain activity to make more money. Less intrusive "wearables" such as headsets are already available to buy. And the growing use of artificial intelligence technologies, which work by harvesting information from the internet. has sharpened concerns about what could happen if the bots get access to what's going on in people's heads.