John Oliver

John Oliver highlights Sinclair Broadcast Group-owned TV stations that have aired "must-run" segments with a right-leaning slant on HBO's "Last Week Tonight" Sunday, July 2, 2017.

(HBO video still)

John Oliver says the largest owner of local TV stations in the country shouldn't be trusted.

The HBO host dedicated nearly 20 minutes of Sunday's "Last Week Tonight" to criticizing Sinclair Broadcast Group, which owns CNY Central in Syracuse. Oliver highlighted the "must-run" segments that stations across the country air, including right-leaning political commentary by "snowflakes"-hating former SBG executive Mark Hyman and President Donald Trump's former adviser Boris Epshteyn.

Oliver played a clip that aired in Syracuse and other markets before the 2016 election, blaming the Democratic Party for slavery, Jim Crow laws and the Ku Klux Klan.

"Hold on, Democrats gave this country slavery? It's a little more complicated than that," he responded. "Sure, someone gave me this haircut (when he was on Comedy Central). But I'm accountable for being comfortable with it, liking it, and keeping it around for a morally repugnant amount of time."

Oliver also blasted the broadcast company's mandated "Terrorism Alert Desk" segments, which he accused of making Muslims synonymous with terrorists. He also pointed out a recent story that claimed ISIS chopped teens in half with a chainsaw was never confirmed by any credible news or government agencies.

"I did not know it was possible to dip below the journalistic standards of Breitbart," he quipped.

Oliver said his main concern is that Sinclair-owned stations are airing content with a political agenda without making it clear that there's a bias behind it, while Fox News viewers expect the cable news network's content to be conservative. (Fox recently dropped its slogan of "fair and balanced.")

Some stations reportedly try and air Sinclair content during low viewership times or alongside ad breaks, but local newscasters are still given scripts to introduce those segments.

Sinclair owns or operates 176 TV stations, including NBC 3 (WSTM-TV), CW 6 (WSTQ) and CBS 5 (WTVH) in Syracuse, and recently struck a $3.9 billion deal to acquire 42 more stations from Tribune Media, including WGN America. Oliver called it "the most influential media company that you've never heard of," reaching an average of 2.2 million households in larger markets -- more than Fox News.

Oliver still praised local news for doing "a lot more with a lot less," pointing out that investigative TV reporters can sometimes break stories that national media miss. Oliver also said he often relies on local newscasts while researching stories for "Last Week Tonight," frequently including clips to illustrate his points (or crack jokes). For example, on Sunday, he praised a station that had a producer move around a cardboard cutout of a black bear in a field to demonstrate a reported bear sighting.

CNY Central, bought by Sinclair in 2013, declined a request for comment in May when The New York Times first reported on Sinclair's "must-runs" policy.

Former "The Sopranos" actor Steve Schirripa appeared in a closing segment on "Last Week Tonight" to encourage local stations owned by Sinclair to begin airing disclaimers.

"The people at this station know that local news should never be about cheap scare-mongering or advancing the political agenda," Schirripa said. "It should only be about weather, sports, I-team investigations and human interest stories featuring cute animals."

Note: Video contains some explicit language not suitable for younger viewers.