More than a year before Facebook and Twitter announced that they had discovered a new foreign influence campaign tied to Iranian state media, a group of volunteer moderators on Reddit noticed a peculiar pattern of submissions.

Some Reddit users were repeatedly posting divisive political rhetoric from a group of obscure news websites. That effort led a Reddit moderator from California named Alex Brown and a small team of volunteers to investigate. Using publicly available data about who started the news websites, they were able to find evidence of a wide-ranging propaganda network across the social news site with ties to Iran.

Brown and other amateur researchers notified Reddit, but the website, the fifth-most visited in the U.S., according to data from Amazon’s Alexa analytics, did not respond.

On Tuesday, Facebook and Twitter announced that the websites that Brown had tracked could be traced back to Iran state media, and purged the accounts from their service.

"I tried going to the admins [Reddit's word for paid employees],” Brown said. “I told them about this [eight] days ago. These are hard examples of literal fake news, with clear evidence pointing to the Iranian government."

"If they’re not going to do jack then I’m coming to the media and going to the government. They are attempting to undermine our democracy by posting propaganda."

In total, there were more than two dozen times that the group of Reddit power users, led by Brown, notified Reddit employees of the Iranian disinformation operation, starting in July 2017, according to correspondence viewed by NBC News. The two most recent messages identifying Iranian propaganda to Reddit's paid administrators came on Aug. 16 and 18, just days before Facebook's pulldown.

Brown and other volunteers used a combination of website identification data, called WHOIS data, and tracked similar domain-name registrars and IP addresses to determine the origins of the websites he suspected of being part of a propaganda campaign, which frequently posted fabricated news stories to Reddit. He noted a considerable uptick in both new propaganda accounts and content pushed by the Iranian troll farm, saying they "kicked it into high gear" since August 2017.

Removing propaganda from Reddit may prove tougher than doing so on most other sites. The website has no explicit rule against state-sponsored propaganda, though users who push propaganda are sometimes banned for breaking rules against spamming — or repeatedly posting links to one website or network of websites.

But the website does have volunteer moderators who run all of its communities, many of whom actively stop efforts to manipulate its system.

Reddit has in recent weeks begun to delete some of the user accounts that were found to have been pushing the Iranian websites.

Reddit provided a statement to NBC News about the propaganda campaigns waged on its site.

"We are aware of recent reports of malicious actors on social platforms. We are investigating our own site and, as we have done previously, will be transparent with our findings,” a Reddit spokesperson said.

A Reddit source told NBC News that it is now considering developing a program that will allow researchers like Brown, who have correctly identified targeted spam campaigns on the platform in the past, to directly communicate with site administrators.

Brown's data set included the websites pulled down by Facebook this week, plus dozens of others. He said a Reddit employee reached out to him to apologize on Thursday after news of the propaganda effort led to a clean-up effort across Facebook, Twitter and Google. The note said that the company "appreciates your thoroughness" and that "you may not have gotten responses to your recent reports from us and that’s not cool."

Brown said he's thankful for the response he received, but still doesn't think Reddit, or any company that controls key web infrastructure like web hosting or social media companies, is doing enough.

"It’s a lot of people’s faults,” Brown said. “There have been a lot of failures across the internet that led to this point.”

Iran's propaganda operation most effectively targeted the /r/WorldNews community, the site’s third-largest subreddit with more than 19 million subscribers, and also had recent success pushing content to smaller Reddit groups.

The disinformation operation drew from the same playbook as the Kremlin’s 2016 foreign influence campaign, posing as members of both the American right and left to highlight Iranian government interests. Iranian imposter content on the anti-Trump subreddits like r/MarchAgainstTrump gained considerable traction. Posts amplified by the disinformation effort saw the second-most traction in the Spanish-language subreddit r/podemos, a community for a left-wing political party in Spain.

"It was pretty easy to tell what the angle was here: pro-Palestine, pro-Iran, anti-Israel, generic anti-America sentiment or articles about exposing the evils of the West," Brown said.

Josh Russell, an independent researcher who studies misinformation campaigns, found that some Reddit users pushed hundreds of posts from Iranian websites.

I pulled the data for these domains on reddit.

libertyfrontpress[.]com

institutomanquehue[.]org

criticschronicle[.]com

usjournal[.]us

britishleft[.]com

rpfront[.]com



Top authors and Top subreddits. pic.twitter.com/OXOCacnLze — Josh Russell (@josh_emerson) August 23, 2018

Russell also noted that the tone of some posts had shifted recently toward staunchly backing anti-Trump politicians since the administration’s withdrawal from the Iran nuclear deal. One user who mostly pushed content from the Iranian sites even created a fledgling community devoted to Democratic House nominee Alexandria Ocasio-Cortez, called r/ocasio_cortez, that failed to take off.

Users on Reddit seeking to report spam content, suicide and terror threats, or other banned content like revenge porn, typically have to go through an outdated system in which they message a group of moderators on a now-defunct Reddit community called r/reddit.com. Years ago, Brown sometimes received responses for flagging the spam campaigns this way, but he had been ignored by Reddit administrators since the disinformation ramped up.

As a moderator of some communities, he started noticing fake information, including fabricated quotes, posted in highly ranked news articles in some of the subreddits he oversaw. In some cases, he said, he reached out to activists who were quoted in articles who told him, "we have never heard of that site before and we didn't talk to them, either."

"That's when I knew there was an extremely high-volume racket going on," he said.

Brown worked with Russell, an Indiana-based researcher who provided news organizations with datasets over the last year to pinpoint Russian propaganda on Reddit and Twitter, in identifying some of the Iranian campaigns.

Both Brown and Russell said the groups share many similarities, including smaller website-hosting providers and domain registrars, which helped them zero in on the perpetrators. Russell said he believes Reddit needs to be more proactive about foreign powers looking to use its site to wage an information war.

"I mean we are talking about the fifth-or-so most-visited site on the internet here,” Russell said. “To know that users who want to help them keep disinformation, especially foreign influence campaigns, off the platform have been ignored is angering to say the least.”

"But then for them to say it was 'just spam' is complete BS."