The Consumer Financial Protection Bureau (CFPB) has expanded its investigation of for-profit institutions with a broad inquiry received last week by ITT Educational Services Inc., according to a corporate filing. Corinthian Colleges Inc. is responding to a similar probe. The new federal watchdog group has been tight-lipped about the investigation, but its director has spoken out in the past about colleges with institutional loan programs that have had high default rates. And both ITT and Corinthian have been criticized by consumer advocates for their lending practices.