In his final show of 2016 season, HBO comedian John Oliver devoted the entire episode to coming to terms with Donald Trump’s unexpected victory. “How the f— did we get here, and what do we do now?” he asked.

After running through a list of some of the “alarming” campaign promises Trump has made over the past year-and-a-half—including deporting millions of illegal immigrants, banning Muslims from entering the U.S., advocating bombing civilians, and promising to limit the freedom of the press—Oliver swatted away pundits’ urging Americans to “give Trump a chance.”

He said, “it can feed into the normalization of Donald Trump. And he’s not normal. He’s abnormal…So giving him a chance in the sense of not speaking out immediately against policies he’s proposed is dangerous—because some of them are alarming.”

In the course of the episode though, Last Week Tonight host shone a light on the role social media, especially Facebook, may have played in tilting the election in Trump’s favor.

The comedian noted in passing the much-dissected role played by cable news networks, pointing out that CNN Worldwide president Jeff Zucker did admit that his network likely erred by airing too many of Trump’s speeches and rallies in full, without any comment (or pointing out inaccuracies.)

 

Instead, Oliver spent more time lamenting the fact that many people now get their news from what he called “micro-targeted” media, noting that “fake facts circulate on social media to a frightening extent.”

He cited a study claiming that 44% of Americans get news via Facebook, with Oliver pointing out the extent of misinformation being spread on social media platforms in general. Fortune‘s Mathew Ingram recently wrote about the massive spread of hoaxes and misinformation on Facebook and how completely or mostly false news stories were shared on Facebook to such an extent in recent months that the social media platform is now taking heat for unfairly influencing the election results.

So far, Facebook CEO and cofounder Mark Zuckerberg has steadfastly refuted any criticism that his platform may have swayed the election, arguing that it is not Facebook’s role to be “arbiters of truth.”

“This cesspool of nonsense would be a problem anyway, were it not that one of the people in thrall to it is our future president,” Oliver said on Last Week Tonight. The British comedian then played a series of video clips in which Trump was confronted with the fact that he had misled his followers by citing misinformation from the Internet, either in person at a rally or via social media. In both cases, Trump merely shrugged and claimed it wasn’t his responsibility to factcheck the information he shares.

“Weird conspiracy bullshit has always been bubbling under the surface,” Oliver pointed out. “But, Trump was the first major candidate to harness and fully legitimize it.”