Mysterious metal street signs popped up yesterday in major cities across the country, aiming to make America great again…by banning Republican presidential frontrunner Donald Trump.

Parking signs designating “No Trump Anytime” zones reportedly materialized over the weekend in New York, Chicago, Los Angeles, Washington, D.C., and Miami, installed in high-trafficked and iconic sites like the Capitol Building, Hollywood Boulevard, and yes, Trump Tower.

They appeared simultaneously, blending in so well with legal street signs that passersby slowly started noticing them Monday, posting them online with the hashtag #NoTrumpAnytime.

If they look familiar, there’s a reason: The signs are the handiwork of L.A.-based street artist Plastic Jesus, who erected similar anti-Kardashian signs around Los Angeles in 2015 and went viral with his life-sized Oscar statuettes snorting cocaine and overdosing on the red carpet in recent years.

The Banksy of L.A. has taken aim at celebrity culture, the destructiveness of Tinseltown, Wall Street greed, the food industry, and the War on Drugs in his previous works. This time, he tells The Daily Beast, he found himself increasingly alarmed by the incendiary GOP candidate—and it was time to take his message to some of America’s biggest cities.

“I considered the effect Trump will have on the whole of the nation,” he told me by phone from Los Angeles on Monday, a day after a cadre of volunteers synchronized their efforts to install the “No Trump Anytime” signs across the country. “I think it will be a unilateral disaster.”

“I’ve been thinking as an artist and a street artist of what I can do in terms of a piece that focuses on Trump,” he said. “I didn’t want to be frivolous with it. I wanted to find something that would have perhaps a deeper meaning.”

“I hope it makes people think about what Trump would mean in their city and their state, across the U.S.”

He didn’t specify where the signs should be posted, instead letting his Plastic Jesus Army choose their own inspired and fitting locales.

“I left it up to a group of very able volunteers who were keen to help me,” explained Plastic Jesus, whose inbox has since been blowing up with demand for “No Trump Anytime” signs in other metropolitan areas. “In hindsight, I could have done a hundred in a thousand more cities.”

Tomorrow, he plans to post downloadable PDF files of the image so that people can print out their own and post them in their own neighborhoods. His hope, he emphasizes, is to get Americans mindful of the potential that looms in the very near future should Trump make his way into the White House.

“I’ve been a photojournalist for over 20 years and I’ve traveled to a lot of countries. I’ve seen the effect that politics and policies can have within a nation, which sometimes can be quite devastating,” he said. “Look at Haiti and how some African nations with terrible leadership year after year have an effect on culture, society, and poverty. I think Trump will have a devastating effect on the U.S., which has done so much in the last few decades for equality and culture and fairness. I think he’ll set us back a few decades.”