I read with interest your article on the voucher problem. I had seen this from a feed from an IT website, and as a result of the moneysavingexpert website and forum where these vouchers have been traded in the past.
This is a classic case, if one were needed, of where the direct marketing industry has failed dismally since 2000 to understand the nature of online, how consumers communicate with each other, and the need for security, especially as the solution to this is relatively simple to implement.
To encrypt a voucher code so that it provides additional information about where it came from, what product it is for, or where it can be redeemed can be done with little technical input, but requires the agency to understand about online security. Which of course most still don’t.