It is not possible with current technology to transfer today's large backups in a reasonable time over the internet. Most internet connections are significantly slower at uploading than downloading data. Even with fast DSL, Cable, or dedicated T1 lines the transfer would take several days at best, and saturate your network.  Below is a table illustrating how long it would take to backup over the internet using typical connections - if there was no overhead, a perfect connect was maintained day and night, and you didn't use your connection for anything else.