You could use this analogy to imagine an ad agency as an emotionally disordered person, and you wouldn't be too far off the mark.
Advertisers DO NOT GIVE A CRAP if you are offended, or annoyed, or troubled. All they care about is if they send out 10,000 ads, they get enough increased sales to offset the costs of the ads.
That's the fundamental algorithm behind all the fancy AI technology.
Also, those Muse headbands that read your alpha brainwaves which are used for meditation are dangerous. While they are incapable via (hardware) technical specifications of being able to determine your emotions via code, it can determine whether your mind is in a clear or distracted state. Hence it is used for “meditation” and is considered to be “beneficial” for that purpose.
But, of course it nearly certainly can be used for perpetual harassment, especially since third-party apps can interface with it. Is your mind clear (according to the headset, via code)? Alright, time to bombard you with harassing adtech. Also, it benefits the “designers” of these apps as it makes you more dependent on the device.
The same goes for other consumer EEG devices. The ones that are used with sleep like the Dreem 2 can be used to make your life a total hell through unethical experimentation and more.
I honestly have no hope on such issues. Spotify AB (a Swedish based company), for example, is believed to violate the GDPR. Not only that, they have a patent pending for emotion detection based on your song listening/streaming pattern. There are projects doing this for Spotify doing this exact thing publicly available online at GitHub of course.