In the scope of https://issues.jboss.org/browse/AEROGEAR-803 , we have a method to retrieve an user (based on its id). If the user don't exist it returns null.

There were some suggestions to change that into :

- throwing a runtime exception (seems a bit brutal)

- or returning an empty user (can be confusing)

What is your opinion about this ? 

Seb

ps: the method https://gist.github.com/4510879