Under the Mueller standard, they would be just as illegal if funded by Mexico, or undertaken by an alien (here legally or not makes no difference) acting in the US, unless the alien had registered under FARA.
It appears to me that the FBI and DOJ are selectively enforcing the law against people they have animus toward, and letting their friends skate. They just label it "prosecutorial discretion," and tell you to move on. Of course if you don't, you're next.
So, in reality, Mueller is indicting these people for not supporting Hillary...