On slide 89 it mentions that they delete the data if the user cancels it.

And of course they do. They respect user choice and privacy. Whilst you can be all tin-foil hat and think they are going to keep these "cancelled" photos, I would seriously doubt it.

People also doubted that Facebook retained deleted profiles a number of years ago. Is this an unhealthy opinion to form in an age of growing "cloud" data?

Do they also delete photos from a backend database backup that might've occurred after the upload but before the user cancelled the photo?

The photo isn't store in a database. It's stored on S3. They are not backing up S3, so this concern is misplaced.

Ha, I love the HN reaction to this. Sperging out about Instagram getting photos they're "not supposed to", fake outrage about fake privacy breaches, all while blatantly ignoring this fact.

And of course, I'm sure all this fake outrage has nothing to do with Instagram's recent purchase by Facebook.

If you don't select upload then they can either stop the process if the photo hasn't been uploaded yet OR if its complete then they can send a signal and delete a photo.

But yeah its waste of bandwidth for the user if he decides against uploading the photo.

I imagine they start uploading when you click the greet "tick" button.

Exactly. All this outrage about photos being uploaded without permission is overblown, because tapping the green check button is just the same as clicking a submit button. Instagram just separates the upload process from the process for setting the photo's metadata, which is very intelligent and more efficient.

It isn't submit it's "upload". And it is only overblown outrage now that we know the facts right?

The easy technical workaround would be to pre-send the photos encrypted with a random key, and only send the key after you explicitly click "upload". At least that way you could verify with a proxy that they were, in fact, not seeing photos you haven't sent them the keys for.

Good idea.. they should do this.. Maybe the encryption is too "heavy" for mobile phones? (uses too much battery ore whatever) ?

Or maybe it's just extra work and complexity that so few of their users actually care about.