Madison, Wis.-based Summit Credit Union has filed a class-action lawsuit against Equifax on behalf of credit unions for damages related to the credit-reporting agency’s giant data breach disclosed earlier this month. The suit claims Equifax failed to secure its website, ignored warnings from security experts and took too long to disclose the breach, according to a complaint filed in U.S. District Court.

According to Summit CU, which has $2.8 billion in assets and about 167,000 members, the breach has left credit unions to shoulder the costs of cancelling and reissuing member cards, as well as the expense of lost business and fraud activity on member accounts.

Credit unions may also face new regulatory compliance costs as regulators request additional reports and plans in an effort to protect consumers, Summit alleged. Financial institutions will have to bear the burden associated with fraudulent new accounts created by identity thieves, too, it said.