Same here, noticed a huge spike in bandwidth for my startup's shows hosted on CloudFront. 206 responses are flooding my logs and I moved everything off of CloudFront for my users to triage the cost. This breakdown explains it all: http://cl.ly/image/2H3u3u2O333g Talk about a pain, not to mention the 10x bill from Amazon that came as a surprise.
"I moved everything off of CloudFront for my users to triage the cost." Can you explain more? Was there some cloudfront behavior exacerbating the issue? AFAIK this is just a client (mis)using range requests and CloudFront replying as requested.
After looking more closely at the differences for pricing between S3/CloudFront I realize it's appears cheaper to be on CloudFront. I assumed wrong that CloudFront data-out was billed in addition to S3 because of the way it's notated on the usage page ("AWS Data Transfer (excluding Amazon CloudFront)"). To prove it I ran two reports on CF (left) and S3 (right): http://cl.ly/image/0q0y3u2X0g1a and you can tell where I made the change, as well data is only counted on the service in question and not on both.
Can anyone else confirm the above?