Companies lay out their rules in a document that says "these are the rules". Its generally pretty standard corporate stuff, of course, these rules can also be changed, especially by the person with the most votes... There isn't some independent authority, the company is in control of its owners, outside of any govt regulatory body rules to be followed.

By legal process, I mean, if you're doing illegal stuff you may be able to be kicked out, its all a case by case basis.