It sounds like this field is protected by a permission that anonymous users don't have, but the website gets an un-security-proxied version of the object so it can display the information without a permission check. If anonymous users really should be able to see this information, it should be unprotected.
It sounds like this field is protected by a permission that anonymous users don't have, but the website gets an un-security-proxied version of the object so it can display the information without a permission check. If anonymous users really should be able to see this information, it should be unprotected.