WASHINGTON (AP) — In a city with a long tradition of leftist street activism, Robin Bell has become something of a D.C. celebrity.

Every few weeks, Bell puts messages of protest on the side of the Trump International Hotel. He’s called President Donald Trump a pig and a racist, used smiling poop emojis, and taunted the president with images of his former lawyer, Michael Cohen.

And it’s all legal. Bell doesn’t use paint or posters, but a projector, so there’s no property damage and no crime. Security guards and police may swing by, but they can’t stop him.

His work has turned into an unexpected business opportunity. Activist groups have paid his crew to travel as far away as Finland to project images on prominent buildings.

“One of the secrets to what we do and how we’ve been able to pull it off is that we’re transparent,” Bell said. “We’re not hiding anything.”

The longtime Washington-based activist and professional projectionist first combined his personal passions and technical skills back in 2010. In the midst of the Occupy Movement, Bell projected messages against the conservative Koch brothers onto the walls of Washington’s convention center.

Over the years, Bell expanded and experimented. He tried projecting messages onto the side of the Capitol and the Supreme Court building. In both cases, security chased him off within minutes.

Many high-level government buildings are off-limits for security reasons. But the Trump hotel — just blocks from the White House — is fair game. Bell learned that as long as his crew members are not blocking traffic, obstructing the sidewalk or shining lights in the hotel windows, they’re fine. Hotel security has called police, but there’s not much police can do and the crew is usually gone within about 30 minutes anyway.

“We know we’re allowed to do it. The police kind of know we’re allowed to do it. But it all kind of depends on the officer and their mood,” he said.

The Metropolitan Police Department said in an email that it “will not engage in any enforcement actions regarding light projections” unless there is an indication that a crime has been committed.

A Trump hotel spokeswoman declined to comment and said they have received no complaints from hotel guests about the projections. The White House referred all questions to the Trump Organization, which oversees Trump’s business interests. Emails to the Trump Organization received no response.

Bell’s first projection onto the hotel was a callback to insider-Washington activist history: “Experts agree: Trump is a Pig.” Identical phrasing was used to describe President Ronald Reagan’s attorney general, Edwin Meese, on posters that mysteriously appeared around Washington in 1987 and were later revealed to be the work of Jeff Nelson, drummer for the D.C. punk band Minor Threat.

Bell doesn’t react to every Trump-related controversy, but some do compel him to act. In January, when Trump reportedly complained about immigrants coming from “shithole countries,” Bell projected that word onto the hotel facade, along with smiling poop emojis.

The work with activist groups has turned into an unexpected moneymaker for Bell and his crew. When Trump met Russian President Vladimir Putin in Helsinki in July, the Human Rights Campaign paid to have messages about Chechnya projected on the presidential palace.

On a recent rainy Monday night, the environmental group Defend Our Future hired Bell for a projection onto the front of the Environmental Protection Agency. That would also give him an opportunity to do a projection on his own at the hotel, conveniently located across the street.

Adrienne Cooper, the environmental group’s director, has hired Bell twice to do projections on the EPA building.

“It’s a way to stand out and do something a little bit different,” she said. “The staff of the EPA can ignore some billboard, but it’s harder to ignore a projection on the side of their own building.”

Just before 9 p.m., the four-person crew waited in a parked van on 14th Street with the EPA on one side and the hotel on the other.

When Bell gave the word, the team moved quickly with practiced, almost synchronized, movements. They unloaded a custom-built projection rack — basically shelves welded onto a dolly with two car batteries providing power. The rain picked up as they started, and umbrellas came out. Bell’s crew was accustomed to working through anything but lightning.

They did the EPA projection first. It showed smokestacks spewing pollution along with rotating messages — some cheering the ouster of EPA chief Scott Pruitt. Bell tinkered with the laptop to get the smokestacks to line up with the building’s columns.

Then it was Trump time. The crew turned the projection rig around and moved it across from the hotel’s unused side entrance.

That night’s image was a reference to the 1989 John Cusak movie “Say Anything” with Cohen, Trump’s former lawyer, holding a boom box over his head, along with the tagline “Says Anything.”

Bell had fretted earlier that the image wouldn’t work, but he hooted and applauded at seeing the finished product on the hotel wall. Within minutes, a security guard approached. Crew member Nadine Bloch intercepted the guard and tried to start up a friendly chat. He didn’t engage at all, but filmed the scene with his phone and talked into his wrist.

Bloch described her role as akin to an offensive lineman in football. “I’m the person who gets in the way so my team has time to complete the pass,” she said while laughing.

The projector cycled through the new image and a few of Bell’s older slogans: “Pay Trump bribes here,” ″Resist” and “This is not OK.”

By 10:20 p.m. they were packed and gone. Bell tracked how the images and video they uploaded were resonating on social media.

“The ones that work best are the ones that give people some sort of relief from all this political stress,” Bell said. “It’s a way of grieving and venting publicly.”