The app known as Zello—which allows smartphones to be used as walkie talkies while doubling as a social media chat tool—is used by 150 million people worldwide. The app was also found to be used by some insurrectionists the day they stormed the U.S. Capitol building on January 6th, according to an article published by The Guardian.

The article was written by WNYC’s On The Media reporter/producer Micah Loewinger and Hampton Stall, founder of MilitiaWatch, a website devoted to studying militia groups.

Following that report, the CEO of Zello took the unprecedented step of deleting 2,000 channels used for recruitment and organizing by far-right militia groups, including some based in the tri-state area. The move comes after years of resistance to any kind of content moderation on the app. It also comes as social media giants have attempted to curtail hate speech on its platforms.

Loewinger spoke with WNYC’s Sean Carlson about the investigation, and what he heard on Zello during the violent riots at the Capitol.

You were listening in on a militia group coordinating on January 6th using a public Zello chat room, and heard a woman’s voice throughout. What do we know about who that woman is in the recording?

That's Jessica Watkins. She's a 38-year-old bartender from Ohio. She's also a veteran. She served in Afghanistan and she was one of the people who ended up breaking into the Capitol. And the reason that we caught this recording is because she was communicating on Zello with people who were likely in D.C. and a bunch of other people who were at home. And she just wanted to tell them what she was seeing on the ground.

Yeah, you actually captured the sound of her talking with other Zello users while she was clashing with Capitol Police inside the main rotunda, discussing “training for this.” What kind of training are they talking about?

Man, I wish I knew more about the context around that phrase, but what I do know is that it's pretty common for militias to actually train for combat scenarios. They'll go out into the woods, they'll do target practice, they'll run drills. It's important to take that kind of language with a grain of salt. A lot of far-right militias would like to sound much more sophisticated and professional than they really are. On the other hand, Watkins is a veteran. She would have had real combat training. And so in this case, I may actually take her at her word.

How do you know that the woman speaking in these recordings is Jessica Watkins?

Well, first, we started with her username on Zello, which suggested that she was the leader of an Ohio militia. It also suggested she was a member of a national militia called the Oath Keepers, who are a very radical group that claims to draw current and former military personnel and police. We then found her profile on Parler, that's the right wing social media site that was shut down about a week ago. We found a profile that basically matched everything I just said, a woman who took pictures of herself while she was in D.C. wearing an oath, her patch claiming to be the leader of an Ohio militia. And then I spoke with a reporter named Jake Zuckerman of the Ohio Capital Journal who was able to verify that that Parler account belonged to Watkins. He interviewed her, she admitted to participating in the insurrection, and she actually spoke about breaking in quite candidly. She didn't think that she had done anything wrong.

As we mentioned, The Guardian published your piece afterwards. Zello deleted a lot of these accounts, but it's not the first time that the use of Zello by extremist groups has been exposed, right?

That's right. We at On The Media actually published an investigation into Zello three months ago. And the investigation included a leaked company-wide email from June that told us that the company knew about some of the far right and white supremacist activity on its platform. Zello’s CEO told us over email that he didn't believe it was the role of a private company to censor speech that, you know, there's no objective definition for hate speech. How could a company that is serving 150 million users even monitor all those conversations in real time, anyway? But we're kind of living in a different moment now than we were three months ago. I mean, everyone is sort of taking the notion that social media has helped radicalize Americans in the wake of this horrible insurrection that took place last week. And companies like Twitter, Google, Amazon, Facebook, they are now starting to realize that these excuses for not moderating content on their platform could lead to really dangerous consequences. So I think on one hand, there are some economic incentives. No tech company wants to be associated with the violence that took place last week. And then there's the public outcry. We are asking tech companies to do more to moderate their platforms, to pay attention to the extremists that are using their tools.

Have you learned anything about the involvement of local groups on Zello that are in New York and New Jersey?

I do know that some militia groups that had used Zello were purged in that big 2,000 group ban that we were talking about before. Some of those groups were perhaps not that active on Zello, and a few of them were very, very active. Now that we don't have access to those channels, it might be a little bit harder to follow them. On the other hand, some research shows that when you deplatform extremist groups online, yes, they will try to set up shop on a different platform, but they often lose numbers. So, we will just have to try to find out where they go.

This interview has been edited and condensed.