Digital Trends - Don’t trade your email for that Big Mac coupon! McDonald’s has warned customers to keep an eye out for signs of identity theft after one of its marketing services partners (Arc Worldwide) was hacked. Arc Worldwide managed the fast food chain’s database of customer names, emails, addresses, phone numbers, and other basic information. Luckily, no credit card or social security numbers were in the compromised database, but hackers could use the email listing to send fake or bad mail to customers.