I interviewed for a hedge fund once where my job interview was to write a program that exploited a security flaw like this to make a real time model of what people were paying for diamonds.
Did you get the job?
No. It was a week long, paid interview. After a couple of days I decided not to come back. Mainly because the main project seemed illegal (which I'll admit held some criminal mastermind allure) and I had another job lined up in Japan. In retrospect, I wish I would have done it as the job in Japan was terrible and I've not come across a similar opportunity since.