This is Amazon’s second major outage this year, and given how many sites rely on the service it’s a real nightmare when it goes down. It’s a little concerning to think about some of the other third-party providers that could exhibit similar problems. For example, those using Yahoo‘s YUI library might well be accessing them from Yahoo’s JavaScript site, rather than hosting the files themselves. In the even that these go down, the sites will likely be rendered useless, in a rather ungraceful manner. Fortunately, JavaScript, CSS, and the like can all be easily hosted locally. Hundreds of gigabytes of photos are not so easy to have local backups of.