If corporations are dead-set on being treated as people, then if they are found guilty of a capital crime (e.g., something that increases profits at the cost of human lives), they should be punished in a fashion similar to people arrested, thrown in jail, or executed: their assets frozen, their corporate charters revoked, and any shares in the company seized.
Failing appeals, all frozen assets would immediately be absorbed by the government as fines or redistributed as reparation; the corporation would be effectively dead.
There should be exceptions for companies providing informed consent. For example, a full, honest disclosure of possible risks or dangers to consumers via an easily-accessible means (e.g., an internet site or mail) would protect a company from criminal prosecution.