The Consumer Financial Protection Bureau sued the operator of Zelle, as well as Bank of America, JPMorgan Chase and Wells Fargo “for failing to protect consumers from widespread fraud” at the payment provider, according to a statement on Friday.

CFPB, the government’s consumer financial watchdog agency, alleges customers of the top three banks lost more than $870 million over the seven years that Zelle has been in existence due to the banks’ failures to protect them.

Among the CFPB allegations are that Zelle and the banks failed to implement proper fraud prevention safeguards, allowing scammers to proliferate, and that banks failed to properly investigate customer complaints about Zelle.

Zelle is operated by a company called Early Warning Services, which is co-owned by seven of the largest banks in the U.S.: Bank of America, Capital One, JPMorgan Chase, PNC Bank, Truist, U.S. Bank, and Wells Fargo.