A digital activist has turned the tables on neo-Nazi and white supremacist trolls by using their own tool to track and identify their antisemitic activity online, news and culture site Fusion reported on Tuesday.

According to the report, using the same technology behind the now-banned “Coincidence Detector,” Daniel Sieradski has found a way to out antisemites who launch attacks on Jews and their allies with his “Nazi Detector.”

As reported by The Algemeiner earlier in June, Google Chrome pulled the innocuous-sounding neo-Nazi plug-in after it was revealed that it was being used to track Jews online. Using a special web construction called an “(((echo)))” — three parentheses around the names of targets — white supremacists were able to encase the names of Jews that appeared on a webpage and attack them online. Each new Jewish or anti-white personality identified by the extension was then added to a database of names which was updated regularly.

The extension was uploaded by “altrightmedia,” a nod to the emerging far-Right movement made up of young, tech-savvy white supremacists. Since the use of the (((echo))) became public knowledge, both Jews and non-Jews alike have encased their names in an (((echo))) as an act of defiance.

Using this same logic, Sieradski created a Chrome browser extension that pulls from a database of names and bookends a user’s name in swastikas. After asking a journalist for the original Coincidence Detector database, Sieradski told Fusion he “just hacked away at it for a few minutes” and the Nazi Detector was born.

“I just whipped it together the other day when the idea popped into my head,” he said.

The Nazi Detector database is filled with names and usernames of people listed on the sites of hate-watch organizations — such as the Anti-Defamation League and the Southern Poverty Law Center — as well as notorious antisemitic Twitter accounts, the report said, adding that many of the names on the list are from “proud- neo-Nazis who are eager to be openly identified.”

“[People] have volunteered themselves to be added,” Sieradski said, “sending me antisemitic memes and demanding I add them.”

Sieradski noted that while his plug-in targets white supremacists and neo-Nazis, his extension is different in its intent. “It’s not a secret list of names. If you think you’re on the list unfairly, I’m totally willing to reevaluate and remove you from the list,” he told Fusion. “The goal of the Coincidence Detector was to out Jews who were ‘hiding in plain sight,’ as its creators imagined it. 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.”

While Sieradski has come under attack by neo-Nazis and white supremacists following the release of his Nazi Detector, he said “their idiocy is just water off a duck’s back. But I’m a little disappointed they’re not more enraged about it.”

So far, the Nazi Detector has gathered some 9,000 names.