Question for the group: how to deal with lack of userId?

All, does anyone have a strategy for (anonymously) identifying the user logged into apple music on your site (without a separate account or prompt)?


This would be convenient in many ways - but the particular thing I'm worried about right now is the problem of multiple users on the same computer:


- user A logs in, I download his library and put it in local storage so that it can be there right away when he returns to the site.

- later, user B logs into the same computer and same browser (say at a public internet café computer). He logs in to *his* account, but for at least some period of time I have no way of knowing that the local storage cache is no longer relevant to this user and in fact belongs to an entirely different user, so I should User B the Albums of User A (though not User A's identity). Obviously not a great experience to say this least.


Ideally I would like a GUID representing the user that I could use to key the local storage items I'm using. Is there a way to get one??


Thank you