Halloween is a time for scary things. This year, one of the creepier sights was the scene on Capitol Hill as the big tech companies — Facebook, Google, and Twitter — testified before Congress this week about Russian efforts to use social media platforms to influence U.S. politics.

I hold no brief for Silicon Valley (quite the opposite), but when politicians start to suggest private firms control the free exchange of ideas, every American ought to be concerned.

Capitol Hill is still looking for a scapegoat for Trump’s election. Back in November, when Democrats and the media were reeling from Donald Trump’s unexpected win (as indeed, most still are), Big Tech found itself under scrutiny for allowing the proliferation of “fake news.” Another theory, hatched by Hillary Clinton and still in vogue despite the complete lack of evidence, was that Russia must have colluded with the Trump campaign to swing the result.

Now it turns out Russian interference in American politics was bipartisan. There were anti-Clinton Russian trolls and Twitter “bots,” but there were also Russian agitators on the other side of the political aisle. Witness the shock of Black Lives Matter activists who discovered that several Facebook pages ostensibly devoted to the cause — such as “Blacktivist,” which attacked police and the criminal justice system — had been the work of Russian impostors.

The Wall Street Journal reported this week: “At least 60 rallies, protests and marches were publicized or financed by eight Russia-backed Facebook accounts from Los Angeles to Washington, D.C” in 2016.” Russian agitators promoted Black Lives Matter protests — and Blue Lives Matter counter-protests.

It turns out that Russia’s goal was not to help Trump win — which even the Russians must have thought unlikely — but to turn Americans against each other.

It was not hard for the Russians to find out which buttons to press. The mainstream media deliberately exacerbate social divisions, not just for ratings and clicks, but also to achieve their partisan agendas. As my colleague, Raheem Kassam, noted this week, an ad that ran in Virginia against Republican gubernatorial candidate Ed Gillespie, portraying a white man mowing down minority kids with a pickup, perfectly reflected “CNN’s America.”

CNN is not the only offender, but it is by far the worst when it comes to hyping racial divisions. In 2012, it claimed that George Zimmerman had used a racial slur against Trayvon Martin, when he had not. In 2015, it egged on the Baltimore riots. And who could forget the spectacle of four CNN panelists raising their hands in the “Hands up, don’t shoot” posture in 2014 in solidarity with Black Lives Matter protests, promoting that movement’s original lie.

The “Facts First” network hit a new low this week, when New Day host Chris Cuomo declared that White House Chief of Staff John Kelly had “ignored and rationalized” bigotry by claiming, entirely correctly, that “the lack of an ability to compromise led to the Civil War” and that “Robert E. Lee was an honorable man.”

Kelly never denied slavery was at the core of the dispute. But CNN pilloried him throughout the day merely for stating historical fact.

That sort of behavior is common nowadays on university campuses, where left-wing “snowflake” students complain that they are “triggered” by discussions of uncomfortable ideas — or even by ordinary words, like “master,” that could conceivably have negative connotations in some remote context.

To see several CNN panels melt down over the standard account of the Civil War shows how the ostensibly non-partisan outlet has moved to the far left.

CNN’s news coverage evokes the kind of “news” that Soviet news outlets used to provide about the United States, where the focus was often on racial divisions and social unrest.

Today’s Russian “bots” are just doing what the old communist commissars used to do. The difference today is that they are feeding their propaganda directly into our daily news diet — or, more accurately, they are feeding our own media’s anti-American propaganda back to us.

Yes, that ought to be cause for concern. But the reality, as anyone with a Facebook account knows, is that we do not need Russian trolls, or even CNN hosts, to divide us. We Americans are quite good at fighting amongst ourselves without prompting. Virtual platforms foster nastier squabbles because we do not have to see, in real time, how our words may wound our friends. And the more we live our lives through our smartphones, the worse that becomes.

The fights are also worse because of the behavior of our politicians. Donald Trump says, and tweets, provocative things. But so, too, did Barack Obama. The former president recently complained about “politics infecting our communities.” Yet it was he who urged supporters in 2008 to “talk to your neighbors … I want you to argue with them and get in their face.” It was Obama who told Latino voters to “punish” their “enemies” in the voting booth in the 2010 elections. It was his White House who told Democrats to “punch back twice as hard” against criticism.

We are not doomed to division. Andrew Breitbart believed news outlets should be up front about their biases. But Andrew was also a person who was eager to converse with people who disagreed with him. In today’s polarized media environment, we can still reach out to the other side — as former NPR CEO Ken Stern does in his new book, Republican Like Me.

Facebook, Twitter, and Google have become ideological battlefields that our geopolitical rivals have learned to exploit. But the answer cannot be that government, or the tech giants themselves, should impose boundaries on our conversations.

Rather, we media consumers should exercise caution and judgment. And we need to emulate Andrew Breitbart’s example, and seek friends with different views — offline, if possible.

Joel B. Pollak is Senior Editor-at-Large at Breitbart News. He was named one of the “most influential” people in news media in 2016. He is the co-author of How Trump Won: The Inside Story of a Revolution, is available from Regnery. Follow him on Twitter at @joelpollak.