Back in late 2000, Jordan Seiler was just a photography student studying in New York. After shooting some images he was particularly proud of, Seiler had an idea: Why not showcase his art on the street? So he decided on a whim to have one of his photos printed as a poster and placed it himself over an ad in a nearby subway station.

That single moment of civil disobedience set Seiler on a path that would inspire his work for the next 15 years. Today, not only is he an artist, but he’s also an activist dedicated to taking back public visual space from advertisers and putting control over it in the hands of everyday artists—literally.

As part of his activism, Seiler created PublicAdCampaign, a guerilla initiative to cover up and swap out corporate street advertising with actual art. He does it in part by welding keys that unlock cases on buses and subways that protect ads from “vandals.” Seiler uses those keys himself and shares them with a community of street artists. His slogan? "We Got Keys For That.”

Seiler is featured in Complex’s brand new documentary on street art, No Free Walls, a film about Brooklyn's changing landscape told through the eyes of a street art collective. We sat down with him again to talk about space, the value of art, and why he wants to do away with public advertising. To watch No Free Walls, click here or see below.

COMPLEX: PublicAdCampaign works around, “public space issues surrounding advertising and art.” So what exactly is a public space?

JORDAN SEILER: It’s up for debate, but we define it generally as spaces that aren’t inside of buildings. There are semi-public spaces like the metro system, but my definition is any space—physical or visual—that we share. That includes the sides of buildings, because I can’t avoid seeing a building when I’m walking down the street, so I consider that kind of visual space to be public as well.

We see ads everywhere but can you describe the struggle for public space between public artists and advertisers?

So, my thinking is that public space should only be used for public good. That includes the type of messaging and visual imagery we surround ourselves with. That presents a basic conflict between outdoor advertising's goals and the artist’s goals in public space. The imagery and messaging that we surround ourselves with should push positive outcomes. Art often does that. Advertising, more often than not, pushes negative behaviors and outcomes.

This conversation reminds me of a mural in my neighborhood— a wall with paintings of Nelson Mandela, President Obama, and Shirley Chisholm. It’s on a school and I always appreciate seeing it. Now I’m trying to imagine if it was covered up with an ad for, say, Coca-Cola. Is that the kind of threat we’re talking about?

Yes. Public space, as far as I’m concerned, is space that we all share together. We all pay our taxes in this society and coexist in our cities, and we’re trying to maximize the use of our public resources so that they benefit all of us as best as possible. What you’re describing there is a mural in public space giving you more positive output than potentially having an advertisement there.

The mural makes you feel better and more connected, maybe think thoughts that are more social. Those are all positive outcomes, and that’s being triggered by the use of public space. The negative outcomes of using that space instead for advertising should be obvious. It makes sense that we use public space more like that mural. Once that’s understood, it makes sense to get rid of advertising.

Have you ever seen a city really embrace the idea of using public visual space for the public good?

No, I haven't; not particularly. I have seen some pretty remarkable abuses, though.

In New York, there was one company that initially did a lot of the flyposting around the city a few years ago. That company then decided that they wanted to increase profits by installing street-level billboards all across the city, and they did it illegally without contacting the city and going through the proper permitting process. Through some projects that we did, that company was sued by the city many, many times to the point that the company folded. It’s popped back up, though, as a wild posting company that hits construction sites all across the city. It’s a prime example of how outdoor advertising companies generally operate with an extra-legal expectation for how to use public space. It's a plague, for lack of a better word.

But isn't that the same way graffiti artists operate in the city?

Yes. My concern, though, is that the companies are being funded by multinational corporations that have millions of dollars to broadcast their messages. It's the equivalent of a massive megaphone. Coca-Cola, for example, can just blanket the city by paying these companies to do their bidding. A graffiti artist, on the other hand, has to put in their own time and resources as an individual. I think there’s something more legitimate about that. It’s the difference between writing your name all over the city and telling people to drink sugar water. What’s better for the world? I think having a name all over the city.

So, should advertisers have access to public space at all?

Ultimately, no. I don’t think so.

There are a number of arguments for why they should, but my opinion is that public advertising is detrimental to not only our psychological health as individuals, but it’s also bad for the environment that we live in. It promotes rampant consumption and consumerism, which have been shown to have a negative impact our society. I think the medium itself is bad for the world.

The only reason advertising continues to be a threat to public space is because we believe it profits cities somehow. That’s basically misguided because a lot of the profits that are wrought from advertising in public space go into a few people’s hands. It’s not particularly a public good.

What’s the major takeaway from all of this?

As an individual and an artist myself, I feel like it's very important that we continually request and sometimes demand that our public space is used in ways that are the most beneficial for everyone. That means we also have to think seriously about the kind of society we want to live in. If we think about what the most beautiful, functional, and interesting public environment could be, that environment would not include advertising. It would include artwork and public communication. It would be an environment in which all of our voices are heard.

Get additional insights from Jordan Seiler and learn more about the battle over public space in New York City by watching No Free Walls, a brand new mini-documentary from Complex.

(This interview has been edited and condensed for clarity.)