Extraordinary claims require extraordinary evidence. This tepid references to we can't disclose anything 'because security' is circular logic. Casting aspersions without evidence is a fundamental abuse of due process and basic standards of jurisprudence. It is a witch hunt.
Are we to assume only Russia, China and Iran are running ops and others are innocent sheep? This is like 'villain of the month'. If they truly have the capability bring out all the evidence and identify all patterns of such behavior so people are aware of astroturfing not only by other governments but also their own government and other vested interests.
This is a dangerous game of spreading FUD and poisons the well. Without ironclad evidence it demonizes dissent, diversity, alternative opinions and with it informed discussion. And legitimizes censorship.