The problem here boils down to “Identity” what most refer to as “User Accounts”. To make Identity work its representation in digital form requires:
 Language (signs, syntax, and role semantics) for encoding and decoding information [data in some context e.g., identification]
 signs — for denotation
 document — for holding claims
 notation[s] — for representing claims in a document
 serialization format [s]— for persisting claims in a document
 network protocol (e.g., HTTP) for storing and retrieving document.
With the above in place, and Logic functioning as the conceptual schema (as is the case in the real-world), you end up with a flexible mechanism for entity identification (sign denotation resolving connotation provided by an identification document).
a schema:WebPage ;
schema:mainEntity <https://medium.com/@kidehen#this> ;
schema:description “My Identity Document” .
schema:name “Kingsley Uyi Idehen” ;
schema:sameAs <https://medium.com/@kidehen/> ;
owl:sameAs <https://twitter.com/kidehen#this>, <https://plus.google.com/+KingsleyIdehen#this>, <https://www.linkedin.com/in/kidehen#this> ;
schema:mainEntityOfPage <#this> .
Screenshot illustrating translation of the subject->predicate->object based digital sentences/statements above:
Conclusion: Identity is essential to all apps (from Facebook to Google and across the enterprise). This issue is important, and it boils down to fundamental application design where the following are loosely-coupled and based on open standards:
 Data Access
 Data Representation
 Data Interaction
 Data Visualization .
I’ll stop here for now. If a discussion thread develops, I’ll expand further.