What a perfectly obtuse, technical solution. Is grandma going to solve a captcha in order to sign up on a wordpress blog to view photos of her grandchildren?
Dropbox is "just" a private s3 bucket with s3cmd on a cronjob -- or a million other technical solutions -- but they're a successful business because they nailed the user experience for average joes.
The point of OP's product is that you don't have to cobble together a bunch of hacks to replicate the desired user experience, it's supported out of the box.