One way to look at it: Why wouldn't they use this capability? (Moral qualms?)

Powerful interests, including corporations and foreign powers, have long worked effectively to frame public perceptions, even when their access to the members of the public was as limited as newspapers and a few broadcast TV stations, and filtered through editors. And they did it effectively.

Have they stopped for some reason?

And would they be less effective for some reason? The new tools - direct access to billions of individuals, wide bandwidth, no filters - should make them far more effective.

It's amazing to me that the fact of them doing it isn't well-known (there is plenty of research and evidence) and assumed, but still a question even on HN. Bring it up to most people and they will ostracize/ridicule you - an odd response which I can't explain well, given the evidence, likelihood, and very serious consequences which those same people are unhappy with.

Interestingly, over the last several years powerful interests have worked - successfully - to shut down research on this issue, including at places like Stanford and Harvard.