Excerpt from the related Washington Post article:

“Last Week Tonight” host John Oliver knew he was inviting a legal battle when he used his show Sunday to lambaste one of the country’s largest coal mining companies and mock its chief executive. But it had to be done, he said.

In a 24-minute segment on the decline of the coal industry and President Trump’s tenuous promises to bring it back, Oliver railed against the mining giant Murray Energy Corporation and chief executive Robert E. Murray, who has blamed the industry’s troubles on an “evil agenda” by President Barack Obama.

Before he got going, Oliver offered up a proviso. “I’m going to need to be careful here,” he said, “because when we contacted Murray Energy for this piece, they sent us a letter instructing us to ‘cease and desist from any effort to defame, harass, or otherwise injure Mr. Murray or Murray Energy,’ and telling us that ‘failure to do so will result in immediate litigation.’”