This really underscores Amazon's glaring omission of a billing cutoff on Amazon web services. How hard would it be for them to let me say, cut off my services at $100/month? This is the main reason I'd never use AWS to host anything public.
It's not that simple. First, the problem isn't inherent to virtual hosting services, you could just as easily get hit by this on a bare-metal site, though the interplay of S3 and Google Docs is an added dimension. Cutting off all services opens the door for a class of DoS attacks. Simply direct enough traffic at a single account's assets, and you'll knock them offline for a given billing cycle. If the attack is cheap…
I dont' see this as a real issue (the potential DOS is there, but not a real problem with having a bandwidth metric kill switch). I'd assume this would be a configurable setting and would have to be enabled by choice. In the author's case I'm sure he'd prefer to have is service cut off prior to running up a 1k bill. If one of my test instances started bleeding bandwidth I'd prefer for it to just get killed then to rack up an ungainly bill. If its your production service then don't configure a cutoff.