Walgreen says a list of customers' e-mail addresses has been breached and spam may have been sent out directing customers to enter personal data into outside Web sites.
The company notified customers on Friday that their e-mail had been compromised, but said no other personal information was at risk. Walgreen warned consumers to be aware of potential e-mail scams that ask for personal information. It reminded customers that Walgreen will not send e-mails asking for credit card, Social Security, or other personal identification information.
The company would not disclose the number of customers affected.
"We want to assure you that the only information that was obtained was your e-mail address," the company said, in an e-mail statement to customers. "Your prescription information, account and any other personally identifiable information were not at risk because such data is not contained in the e-mail system, and no access was gained to Walgreens consumer data systems."
Walgreen was not the only company hurt by hackers. On Sunday, Gawker warned subscribers that its database had been hacked and urged them to change their passwords. The company runs a series of blogs on media, technology and other issues and allows subscribers to comment.
On Monday, McDonald's said some of its customers' private information may have been accessed during a data breach. That information included e-mail and other contact information, birthdates and other specifics provided when customers signed up for online promotions. The compromised database did not include any financial information or Social Security numbers. McDonald's did not detail the timing or scope of the breach but says it is working with law enforcement.