Earlier this month, hundreds of drones lit up the New York skyline to promote the “Candy Crush” video game, creating an LED billboard in the sky that thrilled some New Yorkers and frustrated others. Americans, by the way, beware: drone-based advertising could soon be coming to a city near you.

As of November 18, there were approximately 867,000 recreational and commercial drones registered in the United States, and federal authorities expect that number reach 2.3 million by 2024. The Federal Aviation Administration, which regulates U.S. airspace, and other policymakers are focusing on other uses for drones, such as disaster response or delivering lifesaving drugs in rural areas.

But as drones become more and more intertwined with daily life, these large-scale advertising pieces could grow as well. That creates opportunities and challenges for cities trying to navigate America’s increasingly congested airspace, said Britney Kohler, legislative director of transportation and infrastructure at the National League of Cities.

“We’re always thinking about how we use new technologies to innovate, but also, how do we understand what’s happening in our skies from other users who participate?” said Kohler. “There are plenty of opportunities for cities to engage in a clear way with their constituents.”

While the drone marketing industry is still relatively small, large cities will eventually have to deal with it. For example, Capitol Outdoor, an advertising company that coordinated a drone light show for the 2022 National Basketball Association draft in New York City, recently launched its drone offerings. It is initially targeting 10 cities for regular drone shows, including Atlanta, Chicago, Houston, Miami, and San Francisco.

Drone advocates say these light shows could be an alternative to other disruptive displays.

“Aerial advertising for small planes and fireworks are increasingly criticized for their negative environmental impacts and loud noise, and entertainment venues and advertisers are turning to drones to fill this gap,” said said Michael Robbins, the nonprofit’s executive vice president of government and public affairs. International Association of Unmanned Vehicle Systems.

But in some cities, would-be drone sellers could face opposition due to local restrictions on billboards and other aerial advertisements. four states – Alaska, Hawaii, Maine and Vermont – have completely banned billboards, while cities like Houston; Los Angeles; St. Paul, Minnesota; and Kansas City, Missouri, have limited construction of new billboards. Other cities, including San Francisco, Austin and Nashville, have considered banning aerial advertising over the past decade, but have not enacted them.

“Just as we support communities that want to put restrictions on digital advertising, we urge community leaders to weigh the potential negative impacts of drone advertising,” said Mark Falzone, president of Scenic America, an organization in non-profit anti-display.

Yet it remains unclear whether cities will also be hostile to drone shows, which are classified as aerial advertising. After Candy Crush was posted, for example, a New York state senator said he would consider legislation banning drone-based advertising, Gothamist reportedeven though the drones flew from New Jersey to comply with New York City airspace restrictions.

Robbins said that because the federal government regulates drones, cities must work with federal regulators to limit drone-based advertising.

Meanwhile, federal regulators are trying to catch up with the rapid expansion of commercial and recreational drones, said Stephen Luxion, executive director of the Alliance for System Safety of UAS through Research Excellence led by Mississippi State University.

“When creative minds start doing things, the technology always outpaces the regulations,” Luxion said.

Some changes may soon come at the federal level, given that Congress is expected to reauthorize the FAA next year. Drones, officially known as unmanned aerial systems, are at the top of the regulatory discussionand industry leaders are pushing for clarity around the certification and commercial rules of drones.

An FAA spokesperson said in an email that “the safe integration of drones into the national airspace system is a key priority” for the agency.

Cities also want answers. Kohler said the FAA largely expects local law enforcement to “chase roaming drones” in areas where they are restricted, creating an “unfunded mandate” for cities with limited resources. As the next iteration of the FAA focuses, she said officials should “be very careful about how they use their authority” to allow commercial and recreational drones into communities.

Kohler said public officials should update drone regulations “before there are more examples of Candy Crush lighting up the skies.”