In addition to Democrat party elites, presidential candidate Sen. Bernie Sanders (I-VT) now has another establishment machine to contend with — Facebook.

The Wall Street Journal reports that the social network has, in the past few weeks, investigated “suspicious” content that has been posted in support of Sanders on the platform.

Via the WSJ:

Facebook Inc. in recent weeks investigated suspicious content supporting Vermont Sen. Bernie Sanders’s presidential campaign, said people familiar with the matter. But the company was unable to substantiate claims that Trump supporters or Russian actors were involved in any inauthentic activity. Some in Facebook’s leadership were briefed recently on the investigation, some of the people said. It couldn’t be learned whether the probe is continuing. Facebook spokesman Andy Stone said the company investigated a claim by an outside researcher over suspicious pro-Sanders content, among regular reports it generally receives from the research community. While Facebook actively monitors its platform for political disinformation, not all internal inquiries are escalated to senior officials, as this one was, people familiar with the matter said. “We investigate each credible claim we receive, just as we did in this instance when an outside researcher contacted us,” Mr. Stone said. “To date, we have not been able to substantiate the researcher’s claims and we have not been notified by the intelligence community.”

The continued success of Sanders, now widely regarded as the frontrunner in the Democrat party primaries, has sent media and Democrat elites into a frenzy reminiscent of the Republican party establishment’s anti-Trump panic in the 2016 GOP primaries.

MSNBC’s Chris Matthews recently compared Sanders’ win in the Nevada caucus to the Nazi occupation of Paris, drawing fire from Sanders supporters. Elizabeth Warren, meanwhile, has tried to accuse the Vermont senator of sexism, while establishment favorite Pete Buttigieg has attempted to capitalize on allegations that Russia is trying to assist Sanders’ campaign.

Are you an insider at Google, Facebook, Twitter, or any other tech company who wants to confidentially reveal wrongdoing or political bias at your company? Reach out to Allum Bokhari at his secure email address allumbokhari@protonmail.com.