J.P. Morgan Chase & Co. on Saturday put in place daily limits on use for debit-card holders who shopped at Target stores during a 20-day security breach, a move showing how banks may try to contain their exposure to the massive data theft. In a letter to debit card holders posted on its website, Chase said such limitations on spending would be temporary while it reissues cards. For the affected cardholders, the bank is limiting daily cash withdrawals to $100 and putting on a $300 daily purchasing cap. The spending restrictions do not impact credit-card users, the bank said. “We are taking additional measures to protect Chase accounts from the Target breach, and our branches and call centers are there to help these customers,” a Chase spokesperson said. The move to limit spending by Chase customers is the first such step by a major credit card issuer in the wake of the security breach at U.S. Target stores that left as many as 40 million credit and debit accounts vulnerable to theft.