Owner_id if uploaded with anon, service_key or dashboard_user

[RomanRC99]

I was running some analysis on users and the number of files they uploaded and stumbled upon interesting findings:
when maping user email and count of files, i get two things into the "no email" category:

• owner_id is null
• owner_id does not exist in auth_users

`SELECT
id,
bucket_id,
name,
owner,
owner_id,
created_at
FROM storage.objects
WHERE owner_id IS NULL

UNION ALL

SELECT
id,
bucket_id,
name,
owner,
owner_id,
created_at
FROM storage.objects so
WHERE so.owner_id IS NOT NULL
AND NOT EXISTS (
SELECT 1 FROM auth.users au
WHERE au.id::text = so.owner_id
);`

Is there a possibility how to distinguish files uploaded by dashboard user, service role key, or anon user? I was thinking about possible implementation into the owner_id field, but this would break the FK rules, since there are no users for those cases in the auth.users table...so probably some other solution is needed...