Serena Adlerstein didn’t expect her Facebook status to turn into a nationwide movement but somehow her words managed to mobilize thousands of young Jews to the streets, protesting the treatment of migrants in U.S. detention.

“I made an offhand Facebook post like, ‘What if young Jews occupied ICE detention centers and shut them down?’” Adlerstein, 25, told NBC News.

People responded, and by that evening, on June 24, she was on the phone with other young Jews from around the country planning a protest, and hundreds of people had signed up on a Google doc expressing interest in joining.

Adlerstein is not new to activism; she’s an organizer with Movimiento Cosecha, which works to secure better conditions for immigrants. As she watched pundits and politicians debate whether to call migrant detention centers “concentration camps”, she was reminded of the Holocaust refrain she was raised on: “Never Again.”

“Never Again,” she thought, is now.

A week later, on Sunday, June 30, about 200 protesters under the banner of the newly formed Never Again Action protested outside a detention center in Elizabeth, New Jersey. Thirty-six people were arrested that day, and the demonstration had sparked a burgeoning movement.

“My intent wasn’t to start an organization or a long-term movement,” Adlerstein said. But now that Never Again Action has spread across the country, she’s leaning into it.

Since that initial protest, just two weeks ago, Never Again Action has organized more than 10 different protests around the country, in states from California to Rhode Island, and more are scheduled in the coming weeks.

In Boston on July 2, more than 1,000 protesters gathered at the New England Holocaust Memorial, where they marched to a nearby jail where ICE houses detainees. In Philadelphia, 33 people were arrested when they blocked the city’s Fourth of July parade, holding sings like ‘Never Again Means Close the Camps.”

On Tuesday, Never Again Action has planned what they are saying will be their biggest action yet, hoping to bring thousands to the National Mall in Washington.

Members of Never Again Action took to the streets to protest ICE and the conditions of migrants in detention on July 4, 2019 in Philadelphia. Josh Friedman

Never Again Action, which describes itself as a “mass mobilization calling for Jews to shut down ICE and hold the political establishment accountable,” is decentralized, shies away from calling itself an “organization” and is not receiving outside funding from nonprofits or political groups. Using GoFundMe, the group was able to amass over $180,000 in just over a week to support the legal fees of those arrested at the actions.

The group’s organizers are mostly young Jews, staying up late, taking time off work and using their free time to plan the string of protest. They said they are getting practical advice from Movimiento Cosecha, like making sure they aren’t blocking access to detention centers during visitation hours, and crowdsourcing skills from people who want to help and know what it takes to plan large protests.

Migrant detention centers have come under scrutiny amid reports of overcrowding and mistreatment. Conditions were so bad at one Texas facility that following media reports, nearly 300 children were removed after it was reported they had no access to showers for extended periods of time, insufficient food and were lacking in other basic necessities.

On Friday, Vice President Mike Pence saw the conditions Never Again Action is protesting when he visited two federal detention centers in Texas. A group of men detained behind a chain link fence were captured on video, some seen lying on mats covered with silver mylar emergency blankets, while others chanted, “No shower, no shower” to the news cameras as the vice president walked through the facility.

Pence called media reports of the mistreatment of migrants “slanderous” and said he was “impressed” with Customs and Border Protection’s “compassionate work.”

On June 17, Rep. Alexandria Ocasio-Cortez, D-N.Y., referred to the centers as “concentration camps”, which led many mainstream Jewish organization to make statements criticizing her, while politicians on both aisles also condemned her language.

But some Jews stood by her comments. Sophie Hurwitz, 20, a Wellesley College student who was arrested at the Elizabeth protest, said she also calls the detention centers “concentration camps,” but doesn’t think that’s the most important part of the conversation.

“Now is not the time for semantics,” she said. “Now is the time for making sure people are safe, and we have so much work to do.”

Hurwitz said she felt like she had to put her “body on the line,” which is how she wound up at the Never Again Action protest.

Sarah Giskin, 25, who helped plan the action in Philadelphia, said she feels like Jews are being used as “pawns” in the debate about how to speak about the government’s treatment of migrants and refugees.

“Our history of trauma is being exploited to further a right-wing political agenda,” she said.

Giskin, who works as a community organizer in Philadelphia, said being Jewish informs her activism, citing the Jewish community’s deep ties to social justice movements. She joined Never Again Action to “see some of that fire back in the streets.” She hopes as the movement grows, it will “awaken” other Jews, and serve as a “reminder of what our history means and the role we can play in fighting for a better world.”

While it's the young Jews who are on the frontlines, the protests have drawn diverse support within the Jewish community⁠ — parents are bringing their children, rabbis are attending and Yeshiva students have also turned out.

“The Elizabeth action had everyone from nonreligious Jews tattooed all over with a bunch of piercings to people with tefillin and a kippah on,” Hurwitz said.

Organizers are hoping the movement will be inclusive and stay focused on the issues at hand.

“There are probably people there who don't agree on my stance on Israel and Palestine, but we agree on this,” Giskin said. “The goal is to build this movement. ... It’s strategic not to get into every issue.”

Julia Davidovitz, 25, a preschool teacher in Boston organizing with Never Again, said people like her need to act and bring the community together because institutional leaders aren’t.

"This is an occasion where we have been moral leaders,” she said. “We have not seen as much moral leadership from the stronghold of the mainstream Jewish leadership.”

Her message: “Join us.”

Davidovitz wants to see entire congregations join upcoming actions, and invited her rabbi and mom to join her in action.

“This is a crisis no matter what language you use to describe it” Davidovitz said. “We are a community that’s been targeted. We can’t stand by while it happens to others.”