In what may be one of the largest digital security breaches in United States history, millions of customer email addresses have been exposed as a result of a breach at Epsilon. BGR reported on Saturday that TiVo customer email adresses had been compromised as a result of unauthorized access to online marketing company Epsilon’s servers. Following that report, several other companies have come forward to confirm that their customers’ email adresses may have been exposed. Those potentially affected include customers enrolled in Best Buy’s Reward Zone program as well as customers of Citigroup, J.P. Morgan Chase, TiVo, Barclays, Walgreens, U.S. Bancorp, Capital One, HSN and College Board, which represents almost 6,000 different U.S. colleges and universities. “A subset of Epsilon clients’ customer data were exposed by an unauthorized entry into Epsilon’s email system,” Epsilon said in a statement last week. The company insists that only names and email addresses may have been compromised, and that sensitive information such as social security numbers, credit card numbers and passwords were not accessed.