What do an education historian and a late-night comedian have in common?

Shared opposition to the fraud and abuse associated with charter schools and other privatization efforts, of course.

On Thursday, longtime educator and activist Diane Ravitch encouraged her readers to start a campaign of thanks to comedian John Oliver, who devoted a segment of his HBO show Last Week Tonight on Sunday to charter schools and fraud—and is now being targeted by privatizers and other corporate propagandists on Twitter.

Charter supporters are "saying that he 'hurt' children, he savaged children," she wrote, noting that this is "a familiar tactic" of intimidation that she faced after writing about dubious test-scoring methods in New York City school a decade ago.

Ravitch called on her readers to combat the hate by tweeting and emailing Oliver messages of support. "Don't let the charter industry intimidate him," she wrote.

Watch Oliver's segment below:

"Fraud is a feature of deregulation, not a bug," Ravitch added.

"When no one is looking, some people steal. Not everyone steals, but many do. That is why Ohio, Florida, Michigan, and California are scamming taxpayers. No one is demanding accountability. Politicians get paid off by charter friends, then cripple any effort to oversee them Ohio and Michigan spend $1 billion a year to subsidize charter schools, which are lower-performing than public schools."

Education activist and associate fellow at Campaign for America's Future Jeff Bryant noted in an op-ed on Thursday that Oliver's critics miss the point of his segment by calling his arguments outdated, uninformed, and unfair.

"None of Oliver's critics seriously refuted the crux of his argument that there might be something fundamentally wrong by design, rather than by implementation or intent, with the idea that a 'free market' of privately operated and essentially unregulated schools is a surefire way to improve education opportunities for all students," Bryant wrote.