ITT Educational Services, one of the largest for-profit schools in the country, has gotten itself into hot water with the SEC and CPFB for its student lending practices, and the investigation could be a sign of big trouble ahead for the for-profit market. Like all for-profit higher-ed companies, ITT needs to make sure that no more than 90 percent of its income comes from federal loans in order to remain eligible for those loans. Unfortunately, the increasing student debt burden and declining wages have pushed up defaults, scaring off private lenders and making it more difficult for the school to meet this 90 percent threshold.