There's a simple solution.

If Citizen's United stated that corporations are people and, therefore, have Free Speech, it only follows that they have the REST of the freight that 'people' have to deal with.

That is, if your "person" slanders or libels someone, you risk going to jail. Since the corporation isn't "physically" a person, the board running the corporation can be considerd the brains and, therefor, responsible.

If you started giving the CEOs the perp-walk to jail instead of fines that do nothing but hit a balance sheet, you'll see more responsible behavior. Right now, there's no risk whether it's when you make up crap to denigrate a political opponent or kill a dozen people when your offshore rig blows up.

If the CEO of BP was up on 11 charges of manslaughter, things might change. If a $20B fine wasn't the worst the company was looking at, things might change.