People are allowed to lie. Corporations not so much. By not allowing a corporation to lie to its customers or shareholders is that a violation of the constitution?
I don't know -- I'm not an expert on corporation law. I do know that business people are not allowed to cheat their customers or their business partners or their employers, regardless of whether they're incorporated or not. Can you give a specific example of a lie that's illegal for a person to tell in the course of operating a business only if the government construes the lie as "corporate speech"?