"Corporations are people, my friends." (M. Romney)
Corporations are made up of people...corporations are not people. People are people. I own a corporation. It does not look much like any human form I've ever seen.
That's what he meant - that corporations are owned by people. He wasn't speaking literally. He was making the point that the money made by corporations becomes to the benefit of people.
Corporations are owned by people. They are run by people. They employ people. They sell to or serve people. They don't exist but by the will of, through the action of, and for the benefit of, people. That's of course not all people, as for each and every corporation (just as neither your actions nor mine are necessarily the will of and for the benefit of all people ), but some people. And when it comes to the large and widely held corporations (e.g. Exxon), it's a whole lot of people - a lot that don't even realize it.