Morality, ethics and the law are rules which guides individuals and groups in making their choices and judgements. Ideally the individual Satanist is creating their own rules to live by, and views the rules of external authorities with a critical eye and a willingness to break those rules if it is in their self-interest to do so.
External authority creates their rules for which they argue others must follow for two reasons, either to strengthen their control other the ruled, or to seek the approval of a greater authority over themselves. Nothing and nobody creates rules because of altruism, there is always a hidden agenda, the rule is directly due to self-interest. It is often the case that if the individual wants to successfully campaign for a change in the rules by an authority, they will have to appeal to the self-interest of the authority figure.
Whenever a Satanic individual or group argues a point of morality, ethics and law, take into consideration the above observations, watch for the hidden agenda, and keep in mind that the individual Satanist is the ultimate authority, and thus in theory is following their own rules.