That was a problem. So I emailed them to let them know that it was an issue, and received a phone response. I was told "oh, that's not a big deal." I responded by telling them to place a $500 box of cigars in the field.
NOW it was a big deal.
I remember at some point the French computer retailer had an issue when running a "buy 2 get 1 free" offer on blu-rays. One could remove the two bought items from the cart and the free one would remain. Repeat ad-libidum.
Last year Amazon ran an offer where all photographic gear cost $94. All of it, even lenses which retailed for over 13k. https://www.usatoday.com/story/tech/2019/07/19/amazon-prime-... If there is one regret I have in my life, it was not checking the prime day that fateful morning.
Suddenly anything <= 4.99 was open hunt. A month or so later, most item were now 5.01. And possibly uniqueness was now put on credit card number, people can't get more than a handful.
I never could find a figure nor an article in the news but considering how fast this spread around, it was an expensive mistake.
Apparently around 400 orders had been made using it before it was found, which on the scale of things isn't as bad as it could have been
From what I followed it didn't seem malicious, it was a broken attempt to implement a referral bonus
Technically it didn't make any order free actually... just 200$ cheaper and you could use it as many times as you liked.
They made a discount with the correct amount, but it was supposed to require a referral from a much bigger ticket item and they missed that
Once my brother wired 10M EUR from Austria instead of 10M HUF. The exchange rate is above 1:300. Needless to say, he didn't have 10M EUR on that account. Like, ever. Not even close. I still have no idea why the bank let him wire more money than he had especially on this magnitude. They reverted it but we needed to cover the spread which caused an almost 10k eur loss. That hurt.
I have once accidentally copied my one time password into my ebank for payment (I was trying to copypaste the amount from somewhere else, it didn't take, that happens often with PDF and then the clipboard contained the previous copy) and it would've let me do it if I don't stop it at the confirm screen. It's mind boggling.
Unfortunately we'd sometimes get partial or corrupted feeds. Partial feeds triggered investigation and possibly a manual rerun and corrupted ones often halted the system.
Because we only used monthly numbers for reporting, delaying and rerunning any other day was pointless beyond standard root cause analysis to prevent recurrence. And this system had hundreds of feeds so at first there were almost daily issues.
So I added a check to throw out any deviations over two sigma from the median of the last 30 days' good feeds which knocked out 99% of our data quality issues. I got in a boatload of trouble for different reasons but that's another story.
You cannot just drop that line and walk away. Storytime?