Organizations that perform risk management are generally aware of the laws, regulations, and standards they are required to follow. For instance, U.S. based banks, brokerages, and insurance companies are required to comply with GLBA (the Gramm Leach Bliley Act), and organizations that store, process, or transmit credit card numbers are required to comply with PCI-DSS (Payment Card Industry Data Security Standard).
GLBA, PCI-DSS, and other regulations often state in specific terms what controls are required in an organization’s IT systems. This brings to light the matter of compliance risk. Sometimes, the risk associated with a specific control (or lack of a control) may be rated as a low risk, either because the probability of a risk event is low, or because the impact of the event is low. However, if a given law, regulation, or standard requires that the control be enacted anyway, then the organization must consider the compliance risk. The risk of non-compliance may result in fines or other sanctions against the organization, which may (or may not) have consequences greater than the actual risk.
The end result of this is that organizations often implement specific security controls because they are required by laws, regulations, or standards – not because their risk analysis would otherwise compel them to.
Excerpt from CISA All-In-One Study Guide, second edition