What describes a severe or harsh measure put into effect by an organization?

The term that best describes a severe or harsh measure implemented by an organization is "regulations." Regulations often denote strict rules or requirements that must be followed, typically established by authoritative bodies to ensure compliance with laws or standards. They can have significant consequences for non-compliance, thereby giving them a severity that aligns with the description in the question.

Guidelines, on the other hand, are intended to provide recommendations or best practices rather than strict measures. Protocols refer to specific procedures for conducting tasks within organizations, which may not carry the same weight of harshness. Policies encompass a broader range of strategies that an organization adopts, dealing with overall objectives rather than specific, severe measures. Therefore, "regulations" is the most fitting choice for describing harsh actions taken by an organization.