Well, I agree that open host IPs is not very good. However I don't know any blockchain-based system, where IP-addresses of nodes are hidden.
Monero devs, for example, are working on protocol improvement that will hide IP-address for node which first broadcasts transaction, so third-party won't be able to track where the transaction came from. But even with this improvement IPs of blockchain network nodes are public.
On the other hand, considering that every stored piece of data is encrypted, what's the point of hiding the IP-address of host? Yeah, the world knows that this IP-address hosts a storage space for Sia. So what?
I don't believe it is possible that just running a node (and hosting storage) may be forbidden by law. That would be ridiculous. How can you ban running an open-source software?
Also there are Tor and other solutions if you really care to be "invisible".