When Special Counsel Robert Mueller issued indictments for former Trump campaign chairman Paul Manafort and former aide Richard Gates, he may have been doing more than just charging two men.

According to surveillance and privacy expert Barton Gellman, these high-profile first indictments in the special counsel's wide-ranging probe into Russia's interference in the 2016 election is likely part of a larger plan.

"Mueller may have pitched his message today to specific targets he knows and we don't. Other points, not all obvious, apply more broadly," Gellman wrote in the beginning of a Twitter thread on Mueller's strategy.

"What stands out for me is Mueller's strategic use of implicit threat. Not only the ones he names. Not only against Manafort and Gates," he continued before outlining the specific people who could soon be implicated.

"Count 35 against Manafort hits at risk of bank fraud charges against his son in law, with potential financial drain on his daughter too," Gellman wrote. "Counts 38 & 41 share ominous phrase 'together with others.' People may fear he's thinking of them & they won't find out in time to deal."

He went on to claim that "Mueller's team controlled the selection of facts in the [George] Papadoupolous plea," and that "three messages, at least, shaped their choice."

"One: Mueller knows things, some of them about Russia, and has proof. He's warning other campaign witnesses against perjury," Gellman continued. "He's not saying exactly what he knows or how. Uncertainty there inspires dread, may flush out evidence he doesn't even know about."

"Early cooperation," Gellman posited, "will save you from the worst. Mueller could have taken a lot harsher approach to the Papadopoulos facts."

"Classic leverage," he concluded. "He may know what you're hiding. He'll scorch you & yours if you lie. Spill and he'll go easier. Don't wait too long."