It is interesting the first paragraph of Working with Protocols (from Apple’s Developer Website, Programming with Objective-C). Is Apple making a point? :-)

Working with Protocols

In the real world, people on official business are often required to follow strict procedures when dealing with certain situations. Law enforcement officials, for example, are required to “follow protocol” when making enquiries or collecting evidence.

In the world of object-oriented programming, it’s important to be able to define a set of behavior that is expected of an object in a given situation. As an example, a table view expects to be able to communicate with a data source object in order to find out what it is required to display. This means that the data source must respond to a specific set of messages that the table view might send…

-ceo