Agreed. Even if this privacy thing does become an issue, it's can probably be technically addressed. For example, if the only information is in the collision of watermarks, and if those watermarks are not steganographic, then the client app downloading the file could be made to modify the watermark. That way downloaded files will look like ripped files.

Pew! And I was worried about kilobots turning on us. It's them yottabots we should be worried about. Oh, wait a minute.. I think they've so throughly won we call their collective reality.

For you and I further down the food chain, it'll probably be a while. For researchers, though, it's arguably already useful. FTA:

True, 'though I imagine there will always be at least 'individuated asymmetric transparency': some people will be much better at 'managing' their transparency than others.

Not quite. The current wisdom is that You Can Have the Placebo Effect, Even If You Know It's a Placebo.

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Remind me again, why is this story in the idle section?

No part of it. Apologies for being vague. I was trying to say that though in both transaction types, credit card and NFC, your personal information is revealed, in the case of Google's NFC implementation, this personal information will likely be fed into a live, real time "adworks" infrastructure that cross-correlates this information with information unrelated to the transaction (GPS location, connecting other dots). I don't imagine the credit card companies are anywhere close to such an infrastructure: their business models are not anchored around selling your personal information, so they have less incentive to build such a personal information capturing pipeline.

The scary thing about this, I think, is that companies like Google and Facebook will only get better at capturing, slicing and dicing this personal information as time goes on: their business models depend on it. And as the tools of their trade become ever more powerful, they will end up in wrong hands. But I digress..

Sure, it's better if you have to tap that button. But you still give up a lot of privacy through this payment method. Every time you pay this way you advertise your identity, your location, and the time of your purchase.

This personal information leakage is a lot different than that the type that can be gleaned from say ordinary credit card transactions. It'll no doubt be captured in a way that makes connecting the dots easier, faster and more real time.

I'd use this technology if it implemented something like digital cash. Until, then, I'll be holding up checkout stand traffic--like the guy in that commercial..

More like ...looking enviously at Google.

I found it clever and funny too.

Tip to moderators: funny is already both interesting and insightful. That's how humor works.

Right. The video didn't explain how this cryptography works. I'm no expert in this area, but I imagine this might work something like this.

Suppose one can devise a crypto scheme in which you need all of the ballots to compute the sum of the choices cast (uncast ballots get a special null value). So to boil it down to the simplest possible example, if there are only 2 choices a and b, and only 2 ballots cast, then sum routine allows us to compute which of the following 3 outcomes occurred: (2, 0), (1, 1), or (0, 2). For the middle outcome (1, 1), we cannot tell which ballot cast which vote..

I can see holes in the strategy I describe, but I bet these cryptographers have devised something cleverer that stands up to the kinds of attack discussed here.

That would be a fundamental flaw, but I doubt it's like you describe it. I don't think you'd be able count the individual ballots yourself: you'd only be able to verify that the declared aggregate count is indeed correct.

Why have one when you can have two for twice the price?