Sen. Tim Kaine (D-VA) criticized the incoming Trump administration on Thursday, particularly Trump’s designated national security adviser, retired Lt. Gen. Michael Flynn, for amplifying conspiracy theories that Kaine branded as “fake news.”

Kaine said Flynn, who has made news for posting conspiracy theories to his Twitter account, including an incredibly bizarre one that claimed his running mate Hillary Clinton was involved in the child sex trade, “traffics in these fake news stories and retweets them and shares them.” Kaine said that sharing such conspiracies shows “a sense of either gullibility or malice” on Flynn’s part.

“These are stories that most fourth graders would find incredible,” Kaine said. “That a national security adviser would fine them believable enough to share them causes me great concern.”

The former Democratic vice-presidential candidate made the comments during a hearing of the Senate Armed Services Committee on cyber threats facing the United States. During the hearing, Director of National Intelligence James Clapper said that so-called “fake news” and propaganda efforts would be included in the intelligence community’s upcoming report to the President on Russian interference in the 2016 election.

Kaine claimed that he had been the subject of what he called “fake news” stories during the presidential election, saying that one such story about him had been shared 800,000 times online.