I've been involved in enough government stuff to know that resources like that don't get spent unless the target is _really_ bad.

The FBI often refers cases with single digit millions in losses to state and local, because the SAs are busy with bigger cases.

Does it matter if they do the same thing (or worse) openly or covertly?

Russia: https://en.wikipedia.org/wiki/Poisoning_of_Alexander_Litvine...

China: https://en.wikipedia.org/wiki/Disappearance_of_Yingying_Zhan...

Uh, you sure you linked the right article for China?