Banking giants like JPMorgan Chase & Co and Bank of America collectively face more than €1 billion in regulatory fines for using tools to access messages not approved by workers, including email and apps like WhatsApp.

According to "Reuters" quoted by the Economic newspaper, the U.S. Securities and Exchange Commission (SEC) began probing banks' registration practices related to the use of personal devices last year and the Commodity Futures Trading Commission (CFTC) is also examining the issue.

Last year, broker-dealer subsidiary JP Morgan Chase & Co was fined $200 million by the SEC and CFTC for widespread failures to preserve employee communications on personal mobile devices, messaging apps and emails. JP Morgan acknowledged that the conduct violated securities laws. The penalty was one of the first major enforcement actions filed under SEC Chairman Gary Gensler.

For its part, in July, Morgan Stanley tentatively agreed to pay $125 million to the SEC and $75 million to the CFTC to settle investigations into registration practices. The bank has already set aside $200 million of its second quarter profits to prepare for the penalty.

Bank of America, meanwhile, set aside about $200 million in the second quarter for litigation linked to unauthorized electronic messages by employees. The bank said in late July that it was in negotiations with the SEC and CFTC.

The list continues with Goldman Sachs in "advanced discussions" with the SEC and CFTC. British bank Barclays has admitted that it has reached an agreement to pay $200 million to US regulators, and Credit Suisse Grouo said in July that it had set aside a $200 million litigation provision related primarily to record-keeping rules.