now that the commonly used hostnames are published.
The problem I see with that is that apps could easily start proxying the requests though their own servers.
The problem I see with that is that apps could easily start proxying the requests though their own servers.
I could also imagine ways around that. For instance their proprietary SDK could generate the data and cryptographically sign it. Or they could require that app makers set up a special subdomain that points to their ip address. I guess it would only be worth the trouble if enough people care about it.
It is a genuinely tricky challenge from their perspective.