Turning Point USA, a conservative student organization that’s seen as the right’s version of MoveOn.org, has launched a directory asking people to “expose” left-leaning academics at American universities.

The site, called Professor Watchlist, says its mission is “to expose and document college professors who discriminate against conservative students and advance leftist propaganda in the classroom.”

Turning Point USA’s beliefs include “fiscal responsibility, free markets, and limited government,” according to its website. The group’s founder, 22 year-old Charlie Kirk, spoke at the Republican National Convention in Cleveland in July.

Among the academics currently featured in the directory is Melissa Click, a former University of Missouri professor who resigned after a series of protests against racism on campus in 2015, during which she was seen trying to block a student journalist from filming in a tent encampment. Click now works at Gonzaga University in Washington.

Animal-rights activist and philosopher Peter Singer is listed because of his views on abortion. Others are accused of being anti-Semitic. One academic at Occidental College, Lisa Wade, “tweeted negatively” about Turning Point USA, which earned her a spot on the list.

Also in the directory are East Asian historians Bruce Cumings and Orville Schell, included due to their supposed socialist sympathies. Cumings, who now teaches at the University of Chicago, is on the watchlist because he “blames the United States for North Korea’s problems.” Schell, one of the best-known historians of China, is associated in the directory with UC Berkeley, which he left 11 years ago. (He is currently director of the Center on US-China Relations at the Asia Society in New York.)

According to his entry on Professor Watchlist, Schell ”expressed sadness over [Chairman] Mao’s failure to implement his socialist politics properly.” The directly also notes that he once lived in a factory commune in China. In an email to Quartz, Schell said:

Perhaps these dim-witted conservatives can explain how it is that a flaming “socialist” with irremediably “left wing tendencies” such as myself has evoked so much umbrage and disparagement from The Chinese Communist Party for my criticisms of Mao’s extremist socialist policies and their more recent form of “socialism with Chinese characteristics?” Have they bothered to read any of my many books or articles, which universally disparage Mao’s great socialist experiment and the various forms of Leninism and mutant communism that have followed to the point where visas to travel to China are regularly delayed and withheld by Beijing authorities?

Heather Cox Richardson, an American historian at Boston College, posted her response to being included in Turning Point’s watchlist on her Facebook page (although her name is not currently listed on the site). She compared the directory to Senator Joseph McCarthy’s 1950s witch hunt against communist sympathizers in the US, as have others.

“It is ironic that this list would label me ‘leftist.’ In fact, in my public life, I do not identify with a political party, and I work with politicians on both sides of the aisle,” wrote Richardson. “I am dangerous not to America but to the people soon to be in charge of it, people like the youngster who wrote this list.”

Some academics are treating membership of the watchlist as a badge of honor, such as Chris Riedel, a post-doctoral researcher in history at Boston College:

Others have naturally taken to trolling the watchlist, using the hashtag #trollprofwatchlist. A popular tactic is to submit names from Trump University.

This post was updated at 7:00 ET with the statement from Orville Schell.