* Ban all advertisements. (I'm all for it, at this point.)
* Make sure smart-devices make extremely clear that they can be used to show ads, and include trivial instructions to disable ads
Forcing ads onto stuff we pay money for is not okay. Ads to fund free content is probably unavoidable, but even then, it needs to be clear up front what you're subjecting yourself to. Unexpected ads on devices you don't expect them from, can be confusing and disorienting for many people. For people with schizophrenia, it can clearly be dangerous.
And I think this is not just true for smart fridges, but also for those billboards at bus stops that seem stationary at first until they suddenly start to move or talk to you. Ban those please. Or make it clear upfront that they're video. Don't spring this on unsuspecting people.
The other way around — make it clear that the devices are capable of showing ads, and provide instructions on how to opt-in to them (and no cookie-like prompts either)
What would that actually look like though?
Take something that could be considered an ad, but probably most people agree is a good thing. Say you post on here that task X is such a pain in the butt to do all the time as a general gripe, then I say hey, I built a cheap subscription webapp to solve task X easily that you might want to check out. You sign up for it and use it and like it. Seems like everybody wins - you get a problem solved for a small amount of money, I make a little money and get my project used and my work validated etc. But it's still technically an ad.
Lots of stuff like that could be considered an ad. Every "Show HN" could be considered an ad. Suggesting people vote for candidate X or party Y could be considered an ad too - plenty of organizations do pay for actual ads just like that already. Product placements is a type of ad, but it's pretty hard to not do. I don't know how you even make a movie or TV show with people driving cars without showing a particular model of car.
I don't expect that's the kind of ad that everybody is complaining about. Okay, but then how do you legislate the difference? Can you, or anyone, actually write down a definition of the ads you want to ban and the ads you don't? And how will people distort or abuse those definitions? There's billions of dollars in advertising (maybe trillions?), it's not going to all just go away because somebody passed a law. What happens when all of that money gets poured into attempting to abuse such individual personal recommendations? That's already happening on Reddit now, though at small scales for now.