Two New Zealand researchers demonstrated at last Kiwicon conference how to print their own fuel vouchers for fuel discounts. The developed algorithm affects petrol stations operated by New Zeeland national energy provider Z. The duo also demonstrated that with a click of a button on their smart watch, they could produce codes that could be scanned at the fuel station. Z petrol station disabled entering manual barcodes in the past because these codes were being shared online. The researchers said that they didnt use any of the codes on the fuel stations, and warned another not to do it neither.”]
Source: http://securityaffairs.co/wordpress/43619/hacking/hacking-to-obtain-fuel-discounts.html