Welcome to public spaces?
Life involves maybe seeing things, idea, people you don’t like. That’s not inherently bad.
What is allowed and tolerated in that public space is skewed, an unfair. Certainly not balanced.
You are certainly allowed to. Pony up for the ad space if you want to promote the opposite, or advertise something else entirely.
Basically: if you propose a billboard saying "Coca Cola Is Proven[cite] Bad For Your Health" you won't be granted any space.
And even if you find a space not monopolized by such committees, you'll be taken to court by expensive lawyers over defamation or trademark infringment or any other silly thing.
I don’t think that had anything to do with what I said.
Although I’m curious What would a not “skewed” public space looks like, and how do you manage that?
What I was trying to bring across, is that it is "public space" which implies it equally belongs to everyone. But that this is not the case for what you are allowed to advertise. Corporations, or at least "those with connections and/or money" are allowed to be heard a lot more than anyone who lacks these connections or funds.
I call that "skewed". A fair and level "public space" would give anyone, regardless of how much money, connections or lawyers they have, the same ability to present their message.
I am not saying that this would always be a good thing; because this probably means far more advertising noise. It would probably turn our streets into a printed version of twitter. Ugh. I am trying to say that in order to make this less skewed, "those with money, connections and/or lawyers" should also not be allowed to use that public space to deliver their messages. That is a level playing field too!
A paleo fan will think the same about a vegan/carbs ad, and so would an anti-vaxxer about a conventional health poster.
Harmful ideas can, and will reach those who are susceptible to it. I think the right way to oppose harmful ideas, is by gaining the education that would allow you, and others in society to judge such ideas.
The alternative of forbidding ads in public, is essentially censorship and making society even weaker as one way or another, harmful ideas will reach each and every one of us, and when they do, the less susceptible we are, the better.
What if coca cola decided that they didn't like the color of your house, should they be allowed to change it because it can be seen from the public space?
I'm quite certain that if I painted my house white and red with silver curly letters on it spelling "Cola is Sugar" there'd be multiple laws that expensive lawyers can help enforce.
Those laws (trademark, libel, etc) practically grant large corporations from taking over public space. In my country there's committees (seated by advertising industry) that monopolize the space and enforce this in even greater detail. Hell, we even have committees that tell what color you are allowed to paint your front-door (Schoonheidscommitee). This latter, however, is democratically ruled (local govts) so something that Coca Cola has no seat in.
So the answer to your question is: yes. They already can, while the opposite is not possible.
But the question itself is actually a false dichotomy. Me being able to oppose Coca Cola on their own turf: by running a campaign against them, does not imply that Coca Cola can automatically then decide the color of my house.
I live in Israel where there are constant conflicts about what is OK to be shown in public, especially between the religious and non-religious. In Jerusalem for example, some ultra-orthodox often vandalize any kind of poster that shows a woman in it. They just tear-out/spray over the women on the poster. Some are ridiculous cases where they defaced a poster of an old woman who survived the holocaust: https://www.timesofisrael.com/female-holocaust-survivors-por...
Even other groups could be pissed by posters that include things about women's hygiene or show models in swimsuits. In their eyes these are things they make a lot of effort to block from the eyes of their families, and having it in public breaches the culture and education they try to maintain. This is by itself interesting as public adverts can penetrate the most strict censorship that religious groups and cults maintain.
Seculars on the other hand can also be pissed about anti-abortion adverts, religious propaganda, scientology, etc. and ask for them to be banned.
As someone who's trying to be a "free-thinker" and tries to promote it, I think there's no point in hiding in a bubble, blocking yourself from seeing other ideas, even if they're crappy advertisements. All of this as long as the adverts/ideas fit within the aesthetics of the city they're in.
The risk of doing so is essentially losing free-thinking and some sort of communication with isolated social groups.
The question is if you want to give the government such a broad spectrum to censor, in which they'd start judging whether or not a product might be deemed potentially harmful.
Why do we live in a city again?
