Will it be hard to transfer data from CDN?

Currently my web pages and all the user uploaded images are at the same location. Now I want to move all these images to CDN. But I could not move further because of the following clarifications required.

1. Who is the best CDN provider?
2. If I use Amazon S3 for storage and CloudFront for CDN, will there be a possibility to move to another provider easily to dump S3 data to other storage mechanism? Consider that the storage volume is nearly 1 TB of images. How can I dump this data to other storage mechanism easily?
3. If I use cloud storage for storing my images, will there be my control and guarantee for my data? In such case, if I want to move to any other cloud provider, what are the different wa开发者_开发技巧ys for this transition.

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1. that's arguable, for me amazon dose the trick
2. you can easy move files in and out of S3. You can use one of the tools out there (s3cmd, bucketexplorer etc).
3. I know they have a 99,99999 guarantee but you can always use your personal server/storage as the origin for amazon CDN, it's not necessary to use S3.