In Sunday's episode of "Last Week Tonight," host John Oliver took on media consolidation and the not-so-covert conservative bias at Sinclair Broadcast Group's local news stations.

"With Sinclair, they're injecting Fox-worthy content into the mouths of your local news anchors—the two people who you know, and who you trust." —comedian John Oliver"Sinclair may be the most influential media company that you've never heard of," Oliver said of the nation's largest television-station conglomerate. In May, the company announced it was acquiring Tribune Media for $3.9 billion, which will add the Tribune's 42 stations to Sinclair's 173. The acquisition requires regulatory approval from federal antitrust regulators and the Federal Communications Commission.

Watch the full segment below:

A defining component of Sinclair is the "must-run" strategy. Local producers across the country are sent video segments they are required to work into their broadcasts, along with scripts that local anchors use to introduce them. To demonstrate this, Oliver aired several clips of a particularly amusing—and ridiculous—anchor intro for one of the segments: "Did the FBI have a personal vendetta in pursuing the Russia investigation of president Trump's former national security adviser Michael Flynn?"

But after detailing the far-reaching claims on which that segment centered, Oliver identified the overarching issue: "There is real power in hearing your trusted local newscasters using 'FBI' and 'personal vendetta' in a sentence."

Though it's commonly compared to Fox News, Oliver characterized Sinclair's conservative angle as more covert than its cable comrade: "In contrast to Fox News, a clearly conservative outlet where you basically know what you're getting, with Sinclair, they're injecting Fox-worthy content into the mouths of your local news anchors—the two people who you know, and who you trust."

And those nightly news anchors are trusted sources among the American public. Last year the Pew Research Center found that people trust local news sources more than national news sources, family and friends, or social media.

Sinclair also reports on terrorism—"every single day, whether there is something major to report on or not"—through its "Terrorism Alert Desk," which has aired unsubstantiated claims that even the right-wing news outlet Breitbart reported on cautiously. "I did not know it was possible to dip beneath the journalist standards of Breitbart," said Oliver. "That's like being too bad a chef to work at a carnival food cart."

Though Oliver jokes around about Sinclair's content quality and company policies, he also strike a serious note about the consequences of corporate media consolidation: "Should this Tribune acquisition go through, there are going to be even more good journalists having to see their hard work placed alongside terror desk nonsense, just as there'll be even more unsuspecting audience members who will be getting a heaping dose of Sinclair's content, possibly without realizing it."