Per Chosun Ilbo, the lawmakers demanded documents and testimony from the big banks.

At issue is whether banks closed accounts over politics or industry; conservatives allege systematic discrimination, while banks cite anti-money-laundering compliance.

Tension between politicians and Wall Street over supervisory power is a variable for financial regulation broadly; the banks' responses and hearing schedules are next.

Shifts in global banks' account policies can touch Chinese business owners using remittances and corporate accounts. We report the dispute with both sides' positions.