[chinathrow]

> Those are subdomains of 1e100.net, which we know Google owns

Sorry but to the average user, the domain name 1e100.net doesn't ring a bell at all at this point. They would still have to look up the IP in ARIN/RIPE/etc to see that the IP range is effecively owned by a company called Google.

Do you really need a hostname at all? Wouldn't be the ARIN/RIPE/etc entry be sufficient to know who "owns" said IP address?

[detaro]

Google owns IPs that aren't used by Google services (e.g. all the customer IPs on GCE), it's useful to distinguish "Google" vs "hosted by Google".

[chinathrow]

I agree - that again is done via whois normally too.