'Testing it' is a bad idea on two fronts: (a) it's fraud and (b) he's actually gone and told everyone he's going to do it.
If the supermarkets were losing a lot of money on this then I'd imagine they'd move to a more secure barcoding scheme.
Also, I wouldn't be surprised if the 'red' number was related to the weight of the item as this would be needed for the self-checkout tills.
The original barcode (which is still present as part of the discounted code) should allow the tills to look up the weight.
I was just going to chime in a with a similar comment.
I'd love to know if a friendly Tesco store manager would get in trouble for helping to run an experiment with this though. If head office got wind - or were informed by the manager - I'd presume they'd either go mad and threaten/fire the manage in question, or congratulate them. I couldn't predict it either way.
Someone testing the hack could buy two of the same item, one of which has the hacked barcode. The tester could then immediately point out the error, so no fraud actually occurs. A better way of doing this might be to use two people pretending to be a couple, with the first person checking out separately with the correct price. Then the second person could check out with the hacked barcode, then immediately point out the error.
This also gives a good control for the "experiment."
The current "modern" equivalent of swapping price labels is to buy expensive produce at the self-check, but to indicate you're purchasing low-cost produce.
you are an idiot.
You claimed to have "cracked" a barcode, but have merely interpreted some of the numbers. Of course this has been done theoretically as you haven't actually proved that it works.
And it won't work.
Why? Because it's unlikely that a complicated logistics chain such as Tesco that employs half a million employees worldwide and has banking and mobile subsidiaries would let the barcode dictate the price at the register, rather than call it up from their stock management database - the way all POS enabled stores run in the 21st century.
So in your giddy, sensationalist haste, I pray that you "discount" your TV to 1p and get stopped at the gates for sheer idiocy.
Sincerely, Me
Every grocery store I've consulted for or worked at in my youth was operated the same way - there were "manager special" barcodes where the price was part of the barcode, and the price in the database was recorded as 0 with a flag of "barcode encodes price".
Also it wouldn't surprise me at all if it worked. Huge companies make baffling mistakes all the time.
It makes me wonder if, under UK law, it's lawful to eat part of a box of cookies (not measured by weight) while rolling your trolley thru the store, and then paying for the box at checkout.
Typically, it is much easier to show intent if the person actually leaves with the goods (rather than, for example, being stopped at the till), but there is no need for them to do so as a matter of law.
The charges are different, though, since it's fraud and not outright shoplifting.
[1] http://www.nbcbayarea.com/news/local/VP-of-Palo-Altos-SAP-Ar...
[1] http://en.wikipedia.org/wiki/R_v_Morris;_Anderton_v_Burnside
Not worth it...
Not that I approve of this...
The main issue is they just didn't have the infrastructure to do this, remember this was before wifi was abundant. The PDAs which were used for printing discount labels and scanning out-of-stock products (and appear to still be used) synced over Bluetooth. So unless you could setup a Bluetooth network over the whole store it wouldn't have been feasible.
http://www.mercurynews.com/business/ci_20684481/silicon-vall...
DA: "I think he also obviously had way more than any one human could possibly enjoy on their own in a legally acceptable way."
It would often be the case that you couldn't see the whole code on the sticker, but could infer it by removing it and using the original barcode and a bit of guesswork.
I don't advocate the testing of this, and any observant member of staff will have no difficulty catching you out.
[1] http://www.nbcbayarea.com/news/local/VP-of-Palo-Altos-SAP-Ar...
Edit: They also have international operations, but sometimes under different names. In the US they are "Fresh & Easy" according to Wikipedia.
In Prague they are still called 'Tesco', but the UK Loyalty card doesn't scan, shoots an error message instead, and you find yourself explaining in terrible Czech why you even tried to scan it.
We need more of these gentlemen thieves here in the states.
With a suitable smartphone app you could dynamically generate the appropriate barcode on screen, with a set discount (say, 50%). Then just hold your phone over the actual barcode as you scan each item.
This should be relatively hard to spot for any cashier watching, and the weights and stock etc. would all match up.
Of course the CCTV cameras are likely to see you and they're likely to spot what's going on soon enough to cross reference before the footage is wiped.
(* if you were just intending to scam your supermarket anyway...)
x x-xxxxx-x$$$$-x x
