Amazon Outage Takes Down Sites

An outage of Amazon's cloud-based Web service on Wednesday took down a pile of online sites, including Reddit, HootSuite, Foursquare and Quora.

Amazon not only sells books and CD's, the are the hosts many major websites on its web servers through a service called EC2. The "elastic" infrastructure model is designed to scale up automatically to handle giant traffic spikes -- the kind Amazon gets every year during its December e-commerce rush.

Thousands of customers use Amazon's cloud, renting space on its servers. Some of them went down Wednesday in the wake of Amazon's outage.  Amazon's servers are known as some of the most reliable in the cloud.

Amazon representatives did not immediately return calls for comment.