There is no evidence that Nuno F.G. Loureiro, an M.I.T.-affiliated scientist who was shot Monday at his home in Brookline, Mass., was killed in an antisemitic attack. It’s not even clear that he was Jewish.

But in the hours after his death Tuesday morning, a rumor spread that Loureiro was Jewish — and targeted for his pro-Israel politics. In the wake of a mass killing at a Hanukkah celebration in Sydney, Australia, prominent Jewish social media influencers pointed to Loureiro’s death as proof that Jews all over the world were under attack.

The claim appeared to originate from Ira Stoll, the author of a conservative-leaning Substack newsletter called The Editors. In the newsletter and on X, Stoll reported Tuesday that Loureiro was Jewish. On Substack, Stoll attached a screenshot of a Threads post in which a user with that name defended Israel and criticized Hamas.

There was just one problem: The Threads account did not belong to the slain M.I.T. professor. But in an online information ecosystem that rewards virality, paranoia and hot takes — and whose most influential voices are rarely beholden to journalistic ethics — the unverified assertion took hold.

“Loureiro has been reported to be Jewish with strong pro-Israel views,” the pro-Israel account StopAntisemites shared with more than 350,000 followers. Quoting that post, pro-Israel activist Eyal Yakoby wrote to his 250,000 followers on X, “Every Jew must arm themselves.”

Influencers who repeated Stoll’s claim stated it as fact, usually without stating their source of information. If they had, other uses might have seen that Stoll deleted the X post, and edited his Substack article to include a clarification that MIT had clarified the Threads account belonged to a different person.

Instead, the unverified claim spread to other platforms.

“It’s Jew-hunting season,” the pro-Israel food influencer Gabriel Boxer, who goes by Kosher Guru, and the Jewish account Community News told nearly 400,000 Instagram followers in a joint post. Marnie Perlstein, an Australian Jewish influencer, asked in a Reel why the media wasn’t talking about Loureiro’s Jewish heritage.

There was a good reason legacy media that covered Loureiro’s death, among them the Associated Press and The New York Times, did not report that Loureiro was Jewish: It’s not yet clear whether he was. Indeed, some evidence suggests he wasn’t.

At around the same time as Yakoby’s post, a man named Joah Santos tried to shoot down the rumor, saying Loureiro, a friend of his, was not Jewish and would have never spoken about Israel or Gaza. (The Forward has reached out to Santos.)

StopAntisemites’ post had been reposted nearly 2,500 times and received nearly 600,000 views as of this Wednesday evening, and remains visible on X. Santos’ opposing claim, meanwhile, has been seen only 150,000 times.

The idea that Loureiro was Jewish eventually found its way into Yeshiva World News and the Jerusalem Post, which called Loureiro “a Jewish and vocal pro-Israel nuclear scientist.”

Authorities have opened a homicide investigation into Loureiro’s death; no suspects or possible motives have been disclosed. Funeral details have not been announced.

It’s possible that Loureiro was Jewish — neither the university that employed him nor his family has stated otherwise. But no one has been able to say definitively that he was.

The MIT media relations team told the Forward it could not comment on a staff member’s ethnicity or religion. MIT Hillel did not respond to a voicemail left Wednesday evening.

Bruno Cappi, who described himself as a close friend of Loureiro’s in the MIT physics department, said in an interview that he had worked with the professor since 2016 and that his friend had never mentioned being Jewish during that time. Many of their colleagues in the department were Jewish, Cappi said, with last names typical for Jewish ancestry like Friedman and Rosen; if someone were attacking Jews, why would they go after someone whose Jewish identity was not widely known? “It’s all absurd,” he said.

More than 24 hours after Santos and others tried to correct the record, the articles from the Jerusalem Post and Yeshiva World News remained online. The posts by Yakoby, KosherGuru and Perlstein — none of whom responded to requests for comment prior to publication — also remain up as of this publication. (Some X posts have pending crowd-sourced Community Notes underneath stating he is not Jewish and linking to Santos’ post, but those notes are not currently being shown to all users.)

Additional evidence that Loureiro was pro-Israel was also thin: An X user claimed that a Google Street view image of the professor’s home showed a “Stand With Israel” sign. If the image did depict his building, it had been taken three years earlier; it also showed a multifamily building, and Loureiro — if he did live in the building at the time — did not necessarily live in the unit with that window.

Nevertheless, the claim continued to spread. Around 8 p.m. ET on Tuesday — several hours after the posts from Stoll and StopAntisemites — a Wikipedia article was created about Loureiro, which claimed he was born “to a Sephardic Jewish family.” That claim remained on the article for four hours before a different editor removed it.

The post After MIT professor’s killing, Jewish influencers spread unverified antisemitism claim appeared first on The Forward.

In the wake of last weekend’s deadly attack on a Hanukkah celebration at Sydney’s Bondi Beach, some European authorities are stepping up efforts to crack down on antisemitic incitement, with Britain and Germany targeting certain slogans and ramping up legal and security measures.

On Wednesday, London and Manchester police warned that anyone publicly chanting to “globalize the intifada” — a popular slogan among anti-Israel activists that has been widely condemned as a call for violence against Jews and Israelis — will be arrested. 

Local law enforcement said the crackdown comes as the “context has changed” in the wake of Sunday’s massacre in Australia, where gunmen murdered 15 people and wounded at least 40 others who gathered at Bondi Beach to celebrate the first night of the Jewish holiday of Hanukkah.

The British government’s latest effort to confront rising antisemitism comes after a series of deadly attacks earlier this year, including the Yom Kippur terrorist assault in Manchester, which left two Jewish men dead; the firebombing of a march for Israeli hostages in Boulder, Colorado, which killed one person and injured 13 others; and the murder of two Israeli Embassy staffers in Washington, DC.

“We know communities are concerned about placards and chants such as ‘globalize the intifada,’” London’s Metropolitan Police and Greater Manchester Police said in a joint statement, pledging to “be more assertive” and take decisive action against anyone inciting violence.

“Violent acts have taken place, the context has changed, words have meaning and consequence. We will act decisively and make arrests,” the statement read. 

Britain’s Jewish community welcomed the government’s latest measure, with UK Chief Rabbi Ephraim Mirvis describing it as “an important step toward confronting the hateful rhetoric on the streets that has fueled acts of violence and terror.”

Phil Rosenberg, president of the Board of Deputies of British Jews, also praised what he called a “necessary intervention” to tackle the growing hostility and hatred that Jews and Israelis have continued to face over the last two years, following Hamas’s Oct. 7, 2023, massacre across southern Israel.

“We have seen the result of hate-filled slogans in murderous attacks around the world, including in Manchester, the Capital Jewish Museum in Washington, DC, Boulder Colorado, and this week in Bondi Beach,” Rosenberg said in a statement. 

After repeated urging from the Board of Deputies and others, the Met and Greater Manchester Police have announced a tougher, clearer approach to chants and placards such as “Globalise the Intifada”. We strongly welcome this necessary intervention.

Our full statement: pic.twitter.com/kem7RhunRU

— Board of Deputies of British Jews (@BoardofDeputies) December 17, 2025

The Embassy of Israel in the UK also welcomed the government’s move, expressing hope that real action will now be taken “before it can lead to further radicalization and violence against Jews.”

“Calling to ‘globalize the intifada’ is clearly incitement to violence, and a direct line can be drawn between these antisemitic chants and the acts of terror that we have seen against Jewish people worldwide,” the statement read. 

“It is disappointing it has taken such a long time for British authorities to recognize this, and it should not have been on the Jewish community to plead with the authorities to take these threats seriously, only being done so after more Jews have been killed,” it continued. 

Press statement:

The Embassy of Israel in the United Kingdom welcomes the joint announcement by the Metropolitan Police and Greater Manchester Police forces that they will arrest people promoting the phrase ‘globalise the intifada’.

As Israel and the Jewish community have been… pic.twitter.com/0eGn5yvlhl

— Israel in the UK (@IsraelinUK) December 17, 2025

However, this latest initiative has also faced criticism from some, with opponents arguing that it constitutes political repression and violates the right to free speech.

“The statement by the Met and GMP marks another low in the political repression of protest for Palestinian rights,” Ben Jamal, director of the Palestine Solidarity Campaign, said in a statement ahead of a planned pro-Palestinian protest in central London on Wednesday.

“The horrific massacre in Sydney, Australia should not be used as a justification to further repress fundamental democratic rights of protest and free speech in this country,” he added.

UK police have already ramped up security around the country’s synagogues, Jewish schools, and community centers, increasing patrols and implementing additional safety measures to protect communities amid rising tensions.

Shortly after the new measure was announced, local police arrested two individuals “for racially aggravated public order offenses” after they allegedly “shouted slogans involving calls for intifada” at an anti-Israel demonstration in central London, while a third person was detained for obstructing the arrests, the Metropolitan Police said.

UK Prime Minister Sir Keir Starmer also announced on Wednesday that the government had increased funding for Jewish security to approximately $34 million.

Meanwhile, German authorities have also increased efforts to tackle the surge in antisemitic incitement and attacks targeting Jews and Israelis nationwide.

On Wednesday, the Berlin District Court ruled that the use of the slogan “From the river to the sea, Palestine will be free” is a criminal offense, describing it as a symbol of the banned Palestinian terrorist group Hamas.

The ruling came after a 25-year-old man was convicted for shouting the phrase at an anti-Israel protest, found guilty of using symbols of terrorist organizations and inciting violence.

“Anyone who uses this phrase is backing Hamas and its core objective — the destruction of the State of Israel,” ruled presiding judge Susann Wettley.

Although criminal courts across Germany have issued inconsistent rulings on the use of the antisemitic slogan at protests and demonstrations, the latest Berlin District Court decision could allow the German Federal Court of Justice to establish a clear, nationwide legal standard.

Israeli Foreign Minister Gideon Saar praised the ruling, saying that other countries should follow Germany’s example.

I welcome the Berlin District Court’s decision to once again rule that the slogan “From the river to the sea, Palestine will be free” – a Hamas symbol – is a criminal offense.
The verdict is clear: “Anyone who uses this sequence of words supports Hamas and its primary goal – the…

— Gideon Sa’ar | גדעון סער (@gidonsaar) December 17, 2025

“From the river to the sea, Palestine shall be free” is a popular slogan among anti-Israel activists that has been widely interpreted as a genocidal call for the destruction of the Jewish state, which is located between the Jordan River and the Mediterranean Sea.

US Rep. Byron Donalds (R-FL) has firmly established himself as the frontrunner in Florida’s Republican primary for governor, new polling shows, building a substantial lead over the field, which includes anti-Israel investment firm CEO James Fishback. 

The survey, carried out by The American Promise, finds Donalds leading the field with 38 percent support among likely Republican voters. Lt. Gov. Jay Collins trails far behind at 9 percent, while Azoria CEO James Fishback registers 2 percent and former Florida House Speaker Paul Renner garners just 1 percent. Nearly half of respondents, 49 percent, say they remain undecided.

Donalds, a stalwart conservative and strident ally of US President Donald Trump, has established himself as a firm ally of Israel. Donalds expressed support for Israel’s right to self-defense in the wake of Hamas’s Oct. 7, 2023, massacre across southern Israel. As skepticism about Israel has surged within the Republican Party in recent months, Donalds has maintained strong vocal support for the Jewish state.

During an interview with Fox Business this week, Donalds lamented rising antisemitism and anti-Israel sentiment within the country and around the world. 

“This level of antisemitism, this hatred against Jewish people and against Israel, it’s out of control. It’s insane,” Donalds said. 

Donalds also reflected on the antisemitic terrorist attack at Bondi Beach in Sydney, Australia on Sunday, connecting the rise of extremism in Western countries to relaxed migration policies. 

“I mean, this rhetoric around hating Israel, hating the Jewish people, that has to stop because there are real-world consequences. There are crazy people who will carry this out,” he said.

“And to Joe Biden and what he did on the southern border for four years, this is the reason why Republicans and President Trump, we are taking border security so seriously in the face of Democrats who had no problem leaving our borders wide open. It’s actually put the nation at risk,” he added. 

Fishback, a successful investor, entered the gubernatorial race on a slate of populist agenda items. He has raised eyebrows in recent weeks by flirting with members of the antisemitic Groyper movement and signaling acceptance of its leader, Nick Fuentes. 

During a December appearance on Rift TV, a podcast hosted by antisemitic social media pundit Elijah Schaffer, Fishback said that he finds “the audience of young men who follow and watch Nick Fuentes to actually be incredibly informed and insightful.”

After receiving substantial blowback over his comment, Fishback released another campaign video in which he reiterated his defense of Fuentes’s supporters. 

“I want to clarify some comments I made this week rather abruptly” about “the young men in our country who watch and follow Nick Fuentes,” Fishback said. 

“I want to clarify and apologize for absolutely nothing,” he continued, adding that his interactions with Fuentes supporters at his campaign events were “respectful” and “civil.” 

“We had a great conversation, and they have a real pulse for what is going on in the country,” Fishback said. 

Fuentes, a 27-year-old antisemitic internet personality and provocateur, has experienced an increase of popularity in recent months, propelled by a surge of viewership from young men. Fuentes has repeatedly parroted Holocaust denial talking points and suggested that Jewish people are more “loyal” to Israel than to the United States.

Amid the uproar, Fishback released a subsequent video on Tuesday defending the free speech rights of those who believe that Israel is committing a so-called “genocide” in Gaza and that Israeli Prime Minister Benjamin Netanyahu should be considered a “war criminal.” He falsely suggested that those who criticize Israel are facing legal repercussions. 

“Is Netanyahu a war criminal? Did Israel commit genocide? If you say either of those statements in public, you could be convicted of antisemitism. Criticizing a foreign government or any government is always protected under our constitution,” he said. 

Observers have noted that Fishback’s attempts to entice younger, more online portions of right-wing audiences are a microcosm of the growing rupture between Gen Z and older conservatives on the topic of Israel. Recent polls have indicated a collapse of support for Israel among young Republicans, with this portion of the party expressing more skepticism of providing military aid to the Jewish state. Large swaths of GOP voters under 30 have voiced vocal criticism of US support for Israel and the supposed influence of the America Israel Public Affairs Committee, a prominent pro-Israel lobbying group, in US politics.

Recent surveys have also shown a substantial rise of antisemitic views among younger cohorts of the Republican Party.