News of another credit-card security breach over the holidays is likely to rattle shoppers, who have been increasingly relying on plastic over cash and checks.

Neiman Marcus said late Friday that the card information of some of its customers may have been stolen in a cyberattack but that it was unclear how many had been affected. The disclosure followed Target Corp.'s acknowledgment last month that it had been hit by thieves who penetrated its systems for two weeks that included the key Black Friday shopping period.

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