Banks that issued debit and credit cards to customers whose financial and personal data were hacked have joined the litigation against Target Corp. Meanwhile, fresh lawsuits are alleging retailers were well aware of the growing threat of such cybersecurity attacks.

Some lawyers believe the banks could have a stronger case for damages than do consumers, in part because banks typically reimburse customers for any losses they suffer. The banks, however, cite uncompensated expenses associated with lost interest and fees; reimbursements for unauthorized charges; and canceling and reissuing cards.