Calm down, Adam Curtis. I see zero evidence here that researchers can in fact implant anything in someone's dreams. Well, except by playing 3 hours of Tetris. The video "documenting" Coors' effort is a joke ad by Coors bemoaning the fact they can't get into the Superbowl. This is just a bunch of shady researchers trying to gin up some publicity for the !!!!terrifying power!!!! of their work (p = 0.048, one-tailed).
Yeah, the article and letter seem to make a huge jump from companies throwing together tongue-in-cheek advertising campaigns about dreams --- the Burger King "nightmare burger" ad campaign was literally just a burger with a green bun that got them media coverage? --- to smart speakers playing subliminal messages. I guess it's their field, and maybe it's very jarring to them to see advertising even approach it from a distance, but this is almost a parody of the "open letter signed by scientists" trope.
I think they can, but it's not directed as such yet. I mean how often have you had a catchy ad tune or catchphrase stuck in your head? like the McD's whistle / catchphrase, or EA Sports, or the really catchy sex phone line tune, or 0118 999 88199 9119 725... 3
There were people like you 20 years ago that dismissed how absurd it would be that people would willingly buy company microphones connected to the Internet and put them in their houses.
Sure it sounds ridiculous if you frame it like that. A prediction from 2000 that, by 2020, you will be able to control your house with your voice and can ask your computer assistant about the weather doesn't seem so absurd. People have been talking about this type of home automation since the 50s. The hot mics connected to the internet are just an implementation detail, people actually care about capability.