Using second citizenship to go to another country

So piggy backing off my last post - I believe Americans with dual citizenship may be going to their other countries, yes. But they also may be applying for work visas elsewhere using that second citizenship. I have an idea of the countries where these people are and when they’re found to not be where they should be, do I give that list up? Before anyone comes at me about protecting refugees - if this ends up being what’s happening which I sense it is since many have changed their appearances dramatically no doubt in order for a person who looks like them physically to take their IDs - there is no right choice here. Either I stay silent and allow this to happen to others or the other option.