The payment processor then charged the credit union additional fees for a security upgrade, the complaint alleges. If Fiserv billed for security it did not deliver, its customers should be made whole," he said. And, at least one other credit union has alleged the firm used lax online security. As for the credit union lawsuit filed this week, the hacks on FiCare began in 2024, Nerko said. "Fiserv’s systems lack basic security controls," the credit union said in its lawsuit.