I am writing from the perspective of a WvW player. The API-key is there used to verify whether an account is on a certain world or not. However, the basic API-key is providing far more information. E.g. it also contains my characters or a list of guildes I am in. I personally do not like when too much about me is spread. As an example, why shall the names of my characters be known? Needed is only one information: My home world.