I'm getting a suspicious feeling that this product (I'm calling it a product at this point rather than a mitigation as it seems like it's intended to enhance el

I'm getting a suspicious feeling that this product (I'm calling it a product at this point rather than a mitigation as it seems like it's intended to enhance election ad buys rather than actually mitigate a particular risk) wasn't actually designed with Alex Stamos' team's involvement. Which somewhat surprises me considering it's essentially acting as a second-factor for authenticating your physical location. Expanding on your point, the biggest risk I see with postcards rather than really plain security envelopes would be that savvy postal workers may become acquainted with what even ambiguous or anonymous-sender postcards would look like, enabling them to literally deny service (acting, again literally, as a web service DoS) to particular street addresses making election ad buys by suppressing delivery. With time-critical ad purchases just weeks or even potentially <7 days before election day, this would seem like a legal pandora's box, and even anonymizing postcards wouldn't sufficiently mitigate the risk of an employee blackballing a postcard with an exposed PIN or scratch-off on it that's heading e.g. to Koch HQ or MoveOn.org within weeks of election day.