Thaumaturgical magic is as moral as electricity and as ethical as sociology.
Therefore, each culture decides what it considers appropriate behavior by those who wield these powers, then tries to enforce those boundaries. The commonest forms of social control for wielders of all kinds of power are religion, spirituality, and philosophy. Similarly, while purity and innocence do not guarantee protection from malevolent magical attack, in some game systems intense religious piety may provide some divine protection. It is a sad truth that all too many evildoers in history have thought themselves good, and been thought good by others. But it can be amusing to watch how the real-world political attitudes of players and referees get involved in automatic assumptions about the morality of order and anarchy.