A simple scenario that comes to mind is that given a letter, it's now easier to tie it back to the stamp's point of sale. "Who purchased this stamp?" is a very hard question to answer in their current (essentially fungible) form. Adding barcodes makes this much easier.

This assumes that stamps are scanned when sold, to tie their barcodes to the purchaser. That may happen. It may not. But clearly the more scans a stamp gets increases the tracking resolution for a given piece of mail both after AND before mailing. This "before mailing" part is new and opens the door for a much higher level of surveillance.

To give a real world example: Imagine if America had a system like this in place when the Zodiac killer was active in California. A prolific writer of letters to the press, all of Zodiac's barcode-stamped envelopes would open up new potential leads in answering questions like "when was this stamp manufactured" and "where was this stamp originally sold".

I imagine if this system was in place, then they likely wouldn't have written letters to start with.

While I actually do appreciate the importance of postal anonymity, the Zodiac Killer is maybe not the best example to select.

Yeah, I prefer talking about the many illegal drugs you can fit into a stamped envelope.

```

"Who purchased this stamp?" is a very hard question to answer in their current (essentially fungible) form. Adding barcodes makes this much easier.

```

so reselling stamps is not an option ?

Indeed it assumes the stamps are scanned upon sale. Otherwise, at best, what you obtain is "where was this stamp sold", which is completely non-identifying.

But if you think about it for more than ~10 seconds, you remember that stamps are sold in packs of 4-8 at least. They're also often sold in sheets of 50+. All this makes individual scans painful.

So you want to play the devil's advocate and make more assumptions; say, for example, "every stamp could trace back to its original pack, so only one of them needs to be scanned". But if that's the point of this panopticon move, then why put the barcode on the stamp, rather than … the pack itself?

Because you know what always gets scanned? The product's barcode. If I wanted to track people who buy stamps, I would create unique EAN13-compatible barcodes for every single pack sold, always start them with the same number space + some digits for actual different products, and voila, somewhat backwards-compatible, unique tracking on all those stamps without having to deploy a barcode on every single stamp, implement a swap-out scheme, etc.

Of course, maybe someone at GCHQ is reading my comment and thinking "fuck, why did we spend so much money on this scheme again?", but somehow I doubt it.

Then you need to connect the barcode reader of every post office, supermarket and dodgy corner store to the GCHQ mainframe and voila - no more crime.

Instead of issuing every post office, supermarket and dodgy corner store a new barcode reader which can scan the stamps themselves in order to prove the point of the original person complaining of a panopticon?

I think you missed the part where I’m making the argument against this being even sort of practical as a surveillance tool.

That doesn't make sense. What use would scanning the pack be, if the stamps themselves are not associated to the pack?

If anything all the stamps would have two ID in the barcode. One linked to the sales location (always the same) and one as a counter for the individual stamps. That would avoid having to scan every single one.

Seems like there’s an easy work around, you just buy some special issue stamps celebrating British birds or children’s TV characters or whatnot, that don’t have barcodes.

That works while you are still able to buy them for cash, assuming there is no facial recognition on the security camera watching the exchange.

> This card was used to buy this stamp and we have this face on camera doing it.