Investigations by the federal government, media, and States Attorneys General have revealed countless instances of unscrupulous for-profit colleges (particularly those that are run by large, publicly-traded companies), engaging in deceptive, aggressive and manipulative tactics to enroll as many students as possible, without regard for their potential for success or ability to afford tuition, in an effort to maximize profits.
The wealth of sources included on NACAC's Program Integrity page describe how these colleges have adversely impacted students and the taxpayers that fund federal and state financial aid. Additionally, the exhaustive report For Profit Higher Education: The Failure to Safeguard the Federal Investment and Ensure Student Success includes the findings of the Senate Committee on Health, Education, Labor and Pension's two year investigation of the for-profit sector.
http://www.nacacnet.org/issues-action/LegislativeNews/Pages/For-Profit-Colleges.aspx