Facebook said Wednesday that it has disrupted more than 150 deceptive influence schemes since 2017, with Russia the biggest single source, as culprits strive to stay “under the radar.”

The number of coordinated inauthentic behavior (CIB) campaigns derailed at the leading social network ramped up each year since a Russia-linked operation to sway the outcome of the 2016 US presidential election put Facebook on the defensive.

While those behind influence operations (IO) went unchecked on the playing field in 2016, Facebook has invested in hiring, automated systems, and industry alliances over the ensuing years.

“These efforts have pressed threat actors to shift their tactics,” Facebook head of security policy Nathaniel Gleicher said during a briefing on the report.

“They have – often without success – moved away from the major platforms and increased their operational security to stay under the radar.”

As tactics have gone more steathly, the deception campaigns have seen their reach shrink since, by design, they are trying not to be noticed by the social network, according to executives.

From 2017 through the middle of this year, Facebook has exposed and taken down more than 150 covert operations that violate its policy against coordinated inauthentic behavior, according to the report.

“These operations have targeted public debate across both established and emerging social media platforms, as well as everything from local blogs to major newspapers and magazines,” Gleicher said.

“They were foreign and domestic, run by governments, commercial entities, politicians, and conspiracy and fringe political groups.”

The campaigns originated in more than 50 countries overall, with Russia the largest single source accounting for 27 of the deceptive networks, the report indicated.

Iran was the source of 23 CIB campaigns, second to Russia, according to the report.

Meanwhile, the United States was the most common target as well as home to nine such influence operations by fringe political characters, conspiracy pushers, and consulting or public relations firms.

Influence campaigns continue to “push the boundaries of acceptable online behavior” and blur lines between deceit and free speech, Gleicher said.

Those behind IO campaigns were expected to continue to try to “weaponize” moments of uncertainty worldwide, amplifying division around crises such as the pandemic and civic protests.

The US 2020 election campaign brought to the forefront the complexity of separating bad actors behind covert influence operations from unwitting people they co-opt or local folks whose interests are in synch with the deceptive messaging, according to Gleicher.

“We found and removed IO attempting to get authentic voices to post on their behalf,” the report said.

“We also saw authentic voices, including the then-US President, promoting false information amplified by IO from various countries including Russia and Iran.”