The Secret Service says thousands of customers of the DSW Shoe Warehouse chain have likely been put at risk after a breach of the company database.
The Columbus, Ohio-based company says it discovered the theft of credit card and personal shopping information last Friday and reported it to federal authorities.
DSW says it was alerted by a credit card company that noticed suspicious activity.
The special agent in charge of the Secret Service's Cincinnati office says the exact number of persons affected is unknown, but predicts "it's going to be in the hundreds of thousands."
The information was stolen from a database for 103 of the chain's 175 stores. Internet sales from the chain's Web site are believed not to have been affected.
DSW operates a store at the Eastwood Towne Center shopping mall in Lansing Township.