A few years ago, after he starred in “Transformers,” the actor Shia LaBeouf seemed poised to become the next Johnny Depp; instead, he started behaving more like the next James Franco. In 2014, he showed up at the Berlin Film Festival wearing a tuxedo, with a brown paper bag over his head. This was a piece of performance art called “I AM NOT FAMOUS ANYMORE,” which he had created with the artists Nastja Säde Rönkkö and Luke Turner. The trio went on to produce a skywriting project, a hitchhiking project, and, most recently, “HE WILL NOT DIVIDE US,” a piece of anti-Trump protest art, launched on Inauguration Day. The work, according to a statement, consisted of “a camera mounted on a wall outside the Museum of the Moving Image,” in Queens. Members of the public were invited to recite, into the camera, the titular mantra. The statement continued, “The participatory performance will be live-streamed at www.hewillnotdivide.us continuously for four years, or the duration of the presidency.”

The project caught the attention of the hordes on 4chan, an online message board where people post anonymously. One of the most notorious parts of 4chan is called /pol/, which stands for “politically incorrect,” and where the ideologies range from anarchism to fascism and ironic anarcho-fascism. It was the denizens of /pol/ who, last year, turned Pepe the Frog, once a benign cartoon, into a neo-Nazi icon. Many frequent posters there could be called trolls—young, understimulated men whose main goal is to be the chaos they wish to see in the world.

Within hours, 4chan trolls had decided to protest the protest. Or, as one poster put it, “Shia Leboof and a bunch of libtards making an ass of themselves for 4 years live because Trump won. /pol/ fucks with them.” At MOMI, a few trolls infiltrated the crowd, shouting about conspiracy theories and white supremacy. Six days after the live stream began, LaBeouf, who was in the crowd, confronted one of the trolls and got arrested, on camera. On February 10th, the museum cancelled the project, citing public-safety concerns.

A week later, the live stream recommenced, from a location in Albuquerque, New Mexico, across the street from a tire store. “You tried to shut us down in New York—we’re still out here,” LaBeouf shouted into the camera. “How is it cool to be a Nazi now? Shut the fuck up.” The trolls appeared, and vandalized it with spray paint. Within five days, the Albuquerque live stream went dark.

On March 8th, the artists updated their site. “The project moved to an unknown location,” they wrote. “A flag emblazoned with the words ‘HE WILL NOT DIVIDE US’ will be flown for the duration.” The live stream was back up, showing a white flag with black letters against an open sky.

Five minutes later, someone started a thread on /pol/: “Can we find where the flag is?”

“Does the sun come into view?” someone else posted. “We can find angle from the sun path to the ground if we assume the pole is vertical.”

“We might be able to do trigonometry with shadows on the flag,” another person wrote. One of the trolls quickly found a clue: a photo of LaBeouf, taken days earlier, at a diner in Greeneville, Tennessee. Another troll checked the weather in Greeneville; it matched the video. “Anyone else hear the frogs croaking?” someone wrote, referring to the live stream’s audio. This prompted a discussion, including color-coded maps, about local species of cricket frogs.

At 1:56 P.M., a plane flew by on the live stream. “AIRPLANE GUYS AIRPLANE AIRPLANE!” someone wrote. A troll suggested checking Flightradar24.com, a site that tracks flight paths. “IF it’s in greeneville, we’ll see new planes come in from the east and the north,” someone posted. Seven seconds later, another plane flew by, heading south.

“GREENEVILLE CONFIRMED. WE DID IT LADS.”

When they had a good idea of the flag’s coördinates, a /pol/ poster who lives in the Greeneville area drove around and honked, hoping that the noise would be audible on the live stream. It was. Night fell, and the trolls used astronomy to further pinpoint the flag: “The faint star visible next to the flag is Polaris—it has to be since the other star is rotating around it in a perfect circle.”

In the middle of the night, a group of trolls gathered at the exact location, a farmhouse with an open field behind it. Anyone who was watching the live stream at that time saw the white flag come down. A minute later, something was hoisted in its place: a Pepe the Frog T-shirt, and a “Make America Great Again” hat. On March 22nd, the artists reopened the live stream, this time from Liverpool. British trolls got to the flag the next morning. Once again, the live stream went dark. ♦