title: returning null values from a web service call
body: <p>I have a web service API. Some calls return objects containing text fields with information provided by the user. From both a design and a security standpoint, what are the downsides to returning null in those fields when no information has been provided? Is there a clear advantage to always returning an empty string instead, other then simplifying the API by not requiring the client code to check for nulls?</p>