I think it is common for the places that advertise very high storage limits... Dreamhost does the same thing.. though I had to get up to tens of gigabytes, not just 1, before I got smacked down by them..

Sigh. There's never a mod point around when you need it.

every self-respecting network operator has RPF ... enabled at the edge

No, they don't. Not even close.

Gone are the days of spoofing

You haven't been paying attention, have you? The recent DNS DDOS attacks used spoofing to help generate the DOS attacks that hit rates of Gb/s.

Spoofing is still a concern, and every self-respecting network operator should have anti-spoofing filters, but they don't.