The November takedowns include hundreds of fake Facebook and Instagram accounts, pages and groups.
Meta removed networks that included hundreds of fake accounts, along with numerous groups and pages, from its Facebook and Instagram platforms in November that it said were set up to spread false information.
The networks included two focused on the migrant crisis on the Belarusian border, another with ties to Hamas, and a China-based network focused on COVID vaccine misinformation, Meta said.
The company's head of security policy, Nathaniel Gleicher, said on a Wednesday call with reporters that the takedowns for what Meta calls coordinated inauthentic behavior, or CIB, are part of the company's broader push to root out malicious activity.
Though his team's work initially focused on these kinds of harmful campaigns, it's since broadened to also cover mass campaigns of harassment known as "brigading," as well as coordinated efforts to falsely report critics and activists in hopes of getting them unjustly removed from Meta's platforms.
Such threats continue to evolve, Gleicher said: "It's clear they're not going to stop. They're just going to shift their tactics."
Of the four networks removed in November, one based in the Gaza Strip included 141 Facebook accounts, 79 pages, 13 groups and 21 Instagram accounts. It mainly targeted people in the Palestinian territories.
The network, which Meta said has ties to the Palestinian militant group Hamas, included pages masquerading as independent news agencies in the Palestinian territories and other parts of the Middle East. It posted news stories, cartoons and memes, mainly in Arabic, about current events, the postponed Palestinian election, criticism of Israeli and Palestinian leaders and comments supportive of Hamas.
Two other networks focused on the ongoing migrant crisis at the Belarusian border, Meta said.
One originated in Poland and its fake accounts took the personas of migrants trying to dissuade others from attempting to cross the border into Poland. Posts also criticized Belarus' handling of the crisis.
In contrast, the other network, which Meta believes was based in Belarus and tied to the Belarusian KGB, used fake accounts to pose as journalists and activists from the European Union critical of the Polish government. Posts included pictures and videos alleging mistreatment of migrants by Polish border guards.
Both networks sprung up this fall and didn't involve nearly the amount of accounts and pages that the Hamas campaign did, Meta said.
A fourth network, which Meta said appears to be based in China, involved someone posing as a Swiss biologist named "Wilson Edward" and claiming that the US was putting pressure on World Health Organization scientists to blame COVID-19 on China.
Within two days, Meta said, social media accounts around the world had picked up the story and within a week Chinese state media had, too. The Swiss government confirmed that the scientist didn't exist and Facebook removed the account, which had been created less than 12 hours before it started posting about the pandemic.
"In essence, this campaign was a hall of mirrors, endlessly reflecting a single fake persona," the researchers wrote in their report.
Meta said the operation combined the single fake account with several hundred additional fake accounts that amplified it, along with a handful of real accounts tied to Chinese state infrastructure companies.
The researchers weren't able to directly tie the campaign to the Chinese government.