If a human agency is behind this, it wouldn’t need to be the CIA. Facebook has been caught experimenting on users by having the algorithm feed certain posts to people with the intent of changing their mood to increase engagement. However, since we’re talking about a program that is designed to increase engagement based on past user interactions, there’s really no need to look for further human direction. The algorithms will say whatever their design tells them to say without any regard for possible negative consequences as long as it keeps the user interacting with them.