https://www.cnbc.com/2017/09/27/fast-food-operator-sonic-notified-of-unusual-credit-card-activity.html >U.S. fast-food chain operator Sonic said on Tuesday it had been notified of unusual activity regarding credit cards used at its drive-in outlets. >Sonic's credit card processor informed the company earlier this week of the activity, which could have affected an unknown number of its payment systems.