A Mysterious Flier, a Tiny Charity and a Disinformation Campaign at the Border

The two men rang the bell at the Resource Center Matamoros, a migrant aid group in the Mexican border city, and, speaking in broken Spanish, said they were looking for volunteer work.

Security footage shared with The New York Times shows the pair standing on the sidewalk in shorts and flip flops as they talked via speakerphone with Gaby Zavala, the center’s founder. After about half an hour, they left.

Ms. Zavala didn’t know it yet, but the men were not volunteers. They were provocateurs building an online following with hidden camera exposés and ambushes that claim to uncover abuse and election fraud in the American immigration system.

Ms. Zavala realized something was off a few hours later, when the Heritage Foundation, a conservative think tank, uploaded images of a flier with her group’s logo to social media, thrusting her organization into the center of a political firestorm.

The flier, written in Spanish and purportedly found hanging in portable toilets in the migrant camp across the street from the center, carried an explosive message to would-be immigrants: “reminder to vote for president Biden when you are in the united states. We need four more years of his administration in order to remain open.”