The Anti-Defamation League has surveilled leftwing activists and “regularly tracks, profiles and sends threat assessments of individuals” it perceives as a problem, according to an employee account and an internal email obtained by the Guardian.

The May 2020 email was sent from ADL’s head of security to chief executive, Jonathan Greenblatt, and unspecified employees of the Jewish group, which labels itself the “leading anti-hate organization in the world”. A self-styled civil rights organization, it plays an outsize role in shaping public sentiment and national policy around antisemitism, but it has been plagued by controversy in recent years over its attacks on Israel critics and social justice groups.

The memo shows the ADL collected information on a Black Indianapolis activist, Tatjana Rebelle, who worked on Deadly Exchange, a national campaign against an ADL-backed program to send US police officials for training with the Israeli military.

Rebelle, however, said the local campaign on which they worked did not target the ADL, and they had never directly engaged with the group.

In the email, which included a picture and personal information about Rebelle, the ADL head of security, Chris Delia, concluded Rebelle was “a radical with antisemitic and hateful views” but was “not a threat” to the organization. Still, he recommended the file be referred to the organization’s Center on Extremism, which tracks, in its words, “extremist trends, ideologies and groups across the ideological spectrum”.

Rebelle, who left the Deadly Exchange program in mid-2018 to work with a youth climate non-profit, said they were “terrified” for themselves and their family after learning about the 2020 assessment.

“It scared the shit out of me,” Rebelle said, adding that it had had a chilling effect on their activism and what they say publicly. “It stopped me from moving forward because I don’t want to put people in my life at risk – I work with youth, so it stopped me in my tracks.”

The ADL did not respond to specific questions from the Guardian, but sent a statement that said: “The memorandum was inappropriate and withdrawn at the time. ADL does not discuss personnel matters.”

The ADL has come under fire in recent years as it has leveled charges of antisemitism against leftwing Jewish groups, Black Lives Matter, Palestinian rights groups and other organizations critical of Israel. It has increasingly lobbied for federal legislation on antisemitism, some of which critics say is intended to target leftwing Jewish and Palestinian rights groups.

It has become more aggressive since the Gaza war’s outset, but its credibility has also suffered – most recently, Wikipedia’s editors found the ADL could not be trusted to give reliable information on the Israeli-Palestinian conflict.

The memo is the latest evidence that the ADL has spied on, surveilled or tracked its opponents on the left and right. In 1993, the ADL faced multiple lawsuits and an FBI investigation over a nationwide intelligence network it developed over the span of several decades with an investigator on its payroll, Roy Bullock.

Bullock was alleged to have infiltrated or kept files on the United Auto Workers union, Congresswoman Nancy Pelosi, neo-Nazi groups, Mother Jones magazine, the American Civil Liberties Union, the NAACP and many more. He also allegedly sold personal information on US politicians and others to the apartheid South African government at the ADL’s behest. The ADL initially backed the apartheid regime, labeling Nelson Mandela’s party “totalitarian, anti-humane, anti-democratic, anti-Israel, and anti-American”.

In the wake of the far right’s deadly 2017 Charlottesville rally, the ADL, which also tracks white supremacy, claimed it did not “directly” track leftwing groups. However, it put up a post on its website around that time encouraging police to surveil and infiltrate anti-fascist groups.

An anonymous ADL employee who shared Delia’s memo wrote in an email that “threat assessments” Delia developed on Rebelle were conducted regularly. The staffer also noted that “many ADL staff rebelled in horror” and apologized to Rebelle.

Rebelle worked through 2018 for the American Friends Service Committee, which partnered with Jewish Voice for Peace (JVP) on the Deadly Exchange initiative. Rebelle says they helped train local activists on how to address police abuses, worked on immigration issues and raised awareness of the problems with exchange programs between US police and the Israeli military.

Delia states in the 2020 memo that he was asked to assess the activist during a recent “JVP meeting”, referencing the leftwing US Jewish group, a regular ADL target.

In a statement, JVP’s executive director, Stefanie Fox, said: “It’s appalling, though not surprising, that the ADL is spending enormous time and resources attacking one of the largest progressive Jewish organizations in the country and surveilling African American organizers.”

Delia characterizes Rebelle as a “very angry person, looking for a group to belong to”, who complains about “the Black dad she never knew, and white mom and family she didn’t feel she belonged to”. Rebelle also complained about being judged for being bisexual and binational, Delia wrote. He alleges Rebelle “does not like white women, especially suburban white women”.

Delia included a quote from Rebelle’s social media, in which they express they are “no longer in the business of helping white folks cope with their privilege, nor speaking out against the terrorism of white supremacy or state sanctioned murder of Black and brown folks by the police”.

“As always, remember Black Lives Matter, Free Palestine, gender and sexuality is a spectrum, Indigenous rights matter, climate change is real, defund the police, and there is no change without discomfort. Peace upon you all.”

Rebelle said they had been previously targeted by local white nationalists and pro-Israel groups that tried to get them fired from jobs or removed from speaking engagements, but the ADL memo came as a surprise because the group was not involved with her work in Indianapolis.

Rebelle said the ADL was “targeting black queer folks”, and this was evidence of a larger problem with the organization.

“It’s the personal way that they described me … [it] is the same way we would describe a white nationalist or a lone shooter profile,” Rebelle said. “I really was trying to build community and liberation, and we never harm anyone.”

Fox said the surveilling shows the ADL “is simply not credible as a civil rights organization”.

“They are willing to trample on civil rights, smear racial justice activists, and harm progressive movements in order to advance their primary work: ensuring Israeli occupation, apartheid, and genocide go unchecked and unchallenged,” she said.

Tom Perkins