http://www.sciencemag.org/news/2021/06/are-advertisers-coming-your-dreams

Some researchers fear a dystopian scenario in which smart speakers feed sleepers subliminal ads without their consent.

If you’ve ever crammed for an exam just before bedtime, you may have tried something dream researchers have been attempting for decades: coaxing knowledge into dreams. Such efforts have had glimmers of success in the lab. Now, brands from Xbox to Coors to Burger King are teaming up with some scientists to attempt something similar: “Engineer” advertisements into willing consumers’ dreams, via video and audio clips. This week, a group of 40 dream researchers has pushed back in an online letter, calling for the regulation of commercial dream manipulation.