Alerts: what is it that prevents them?

[magic9mushroom]

I know you don't get alerts from the Cult of Sirius, but is this simply because they're hostile or specifically because they're friendly to the aliens?

 

EDIT: I just tested this with save-and-reload on the first alert. I still got an alert from Megapol when they were hostile. That would seem to imply that it's alien-friendliness that stops you getting alerts from the Cult and infiltrated organisations. Would still like confirmation, though.