For more information on the topic I recommend Clair Sullivan’s book Digital Identity: An Emergent Legal Concept, which is available for download at the following link.
In today’s digital environment the concept of identity is an issue of much greater complexity than it was in the days of the offline world. Our digital identity can exist in many forms and for many different purposes. Its existence on the Web becomes a currency that can be unscrupulously traded and abused.
– Professor Stephen Saxby (2014)