This activist found a brilliant way to get back at neo-Nazis using their own tools

They’re called (((echoes)))—a neologism created from the internet’s murky underbelly, where they were once a secret digital tool used by neo-Nazi and white supremacists to “out” Jews online by encapsulating their names in a triad of parenthesis, often by means of a browser extension known as the “Coincidence Detector.

That all changed this spring, when the website Mic published an in-depth exposé on (((echoes))) and the antisemitic corners of the alt-right blogosphere that created it. Following Mic’s reporting, (((echoes))) began popping up all over social media, as users—both Jewish and non-Jewish alike—began appropriating the linguistic frame as a act of defiance against its bigoted progenitors. Internet sleuths went on to uncover the database of names targeted by the Coincidence Detector, and Google eventually pulled the extension from its Chrome web store entirely. While (((echoes))) may still exist as neo-Nazi shorthand in some of the internet’s seedier sections, mainstream exposure has largely neutralized its clandestine effectiveness.

For digital activist Daniel Sieradski, however, (((echoes))) and the Coincidence Detector weren’t just more examples of toxic digital hate—they were the basis for a tool that would repurpose the hate group’s own programming code to use against its makers.

Meet the Nazi Detector.

Like its inspiration, the Nazi Detector is a Chrome browser extension that pulls from a database of online handles, and brackets their names with an easily identifiable mark. But while the Coincidence Detector used (((echoes))), the Nazi Detector is far less circumspect, bookending a user’s name with swastikas.


“I just whipped it together the other day when the idea popped into my head,” Sieradski told me over email. (Full disclosure: we are acquaintances in real life). “I asked a journalist I know who’d saved the archive of the original Coincidence Detector to send it to me, and then just hacked away at it for a few minutes.”

Sieradski began populating the Nazi Detector’s database with usernames pulled from hate-watch organizations like the Southern Poverty Law Center and the Anti-Defamation League, as well as from followers of several major antisemitic Twitter accounts.

Astonishingly, a large portion of the names on Sieradski’s list has come from proud neo-Nazis who are eager to be openly identified.

“[People] have volunteered themselves to be added,” he said. “Sending me antisemitic memes and demanding I add them.” All told, the Nazi Detector’s database has nearly 9,000 entries.

Sieradski was quick to explain that, beyond setting its sights on white supremacists and neo-Nazis, his extension differs from the Coincidence Detector in several important ways. In addition to personally reviewing all names that are added to the database, his database operates transparently. “It’s not a secret list of names,” he pointed out. “If you think you’re on the list unfairly, I’m totally willing to reevaluate and remove you from the list.”

As Sieradski also noted, a crucial difference is intent. “The goal of the Coincidence Detector was to out Jews who were ‘hiding in plain sight,’ as its creators imagined it,” he said. “No one is accusing these Nazis of hiding their online identities — though obviously they’re hiding their real identities because they’re cowards who don’t have the courage of their convictions.”

Sieradski said he’s been inundated with antisemitic harassment online since launching the Nazi Detector—something confirmed by a quick glance at his Twitter feed. Still, he was very sanguine for someone who is being bombarded by hate speech.

“I definitely expected to be targeted, and their idiocy is just water off a duck’s back,” he said. “But I’m a little disappointed they’re not more enraged about it.”