It's easier because.. FB has access to millions of people that universities do not? Because fbook can manipulate the minds, emotions and money and politics of highly targeted groups without anyone knowing and the universities could never do that, or would never do that?

Is it because fbook has less ethics / laws / rules in place? Because universities need to answer to the community they are in and have the fear of pitchforks and loss of funding / donors / non-monopoly and need to think of their future and reputation and fbook does not?

What other reasons could there be?

This is something that indeed, unfortunately, we probably should have had regulators talking about long ago.