"Being prosecuted" is not the same as "being charged" or "being convicted." It could lead to prison time, but if he's a US citizen, the fifth amendment applies (which means you do not have to divulge passwords or information). The prosecution part is a fear and intimidation tactic being used by the fascist government, but whether it even goes to trial is another matter.
It's possible they'll get him on some obstruction charge, and while I suspect this will ultimately amount to nothing, it is nonetheless scary that a hostile government exists with this much global hegemony and is still allowed to use a paramilitary extrajudicial group with virtual impunity.