This is from Perfect Phrases For Customer Service but the issue is also covered extensively in Defusing Hostile Customers Workbook For the Public Sector.
That brings us to the fourth type of customer, regulated customers. Government organizations interact with people in ways that are not oriented toward providing something to individuals, but are involve regulating them for the common good. It might seem like people regulated by the government through licenses, zoning regulations, permits, and other controls are really not customers. We want to include them, because even though government regulate them, they still deserve the best possible levels of customer service. Including this group under the term “customer” reminds us (and, hopefully, government employees) that even when employees are telling people what to do or what they are allowed (or not allowed) to do, they need to apply principles of customer service. This applies to border guards, immigration officials, health inspectors, building code enforcers and to every position you can imagine in the public sector.