Organizations can legally set and enforce usage policies because they have the right to determine how their resources, such as computers and networks, are used. These policies help ensure that the organization's resources are used in a way that is consistent with the organization's goals and objectives, and that they are not used in a way that could harm the organization or its employees. Additionally, many organizations have a legal obligation to protect sensitive information and to ensure that their employees use the organization's resources in a responsible and ethical manner. By setting and enforcing usage policies, organizations can help meet these obligations and protect their interests.