It's tough -- if someone is hitting you at > 1gbps, that exceeds a gigabit ethernet port -- typically on shared services you only pay for that much. Any more than that and it affects all the other customers on the shared network. So yes, Rackspace has the bandwidth for it, but at the same time if you were Rackspace, would you let our DDoS take down the other hosts in the datacenter?

Gigenet / Black Lotus / Prolexic comes in and says -- we have excess bandwidth, we'll take care of it. Then they proxy clean traffic to you. Unfortunately as we are learning, it's also very expensive.