Yes, they'll pay for this mistake through bad press and lost customers.
A punitive lawsuit isn't going to improve anything in terms of making sure they don't do it again.
A punitive lawsuit isn't going to improve anything in terms of making sure they don't do it again.
What's stopping us to say the exact thing in defense of any xyz alleged offender?
I guess the answer is "because it was just a mistake", but (1) not informing their customers promptly when they found they'd made a disastrous security screwup wasn't just a mistake, and (2) since they themselves say they're improving their procedures in response to the incident, it seems clear that there are things they could have done that would have either avoided the just-a-mistake or mitigated its consequences.