In May 2006, McCain was speaking on the Senate floor in support of the Federal Housing Enterprise Regulatory Act of 2005, a plan he had co-sponsored. In the speech, he cited a federal report, saying that "Fannie Mae employees deliberately and intentionally manipulated financial reports to hit earnings targets." He also noted a $3.8 million fine Freddie Mac had recently paid to the Federal Elections Commission over problems with disclosure of its political lobbying.
"These are entities that have demonstrated over and over again that they are deeply in need of reform," McCain said in the speech. He urged senators to support changing how the institutions were overseen by the government. "If Congress does not act, American taxpayers will continue to be exposed to the enormous risk that Fannie Mae and Freddie Mac pose to the housing market, the overall financial system, and the economy as a whole," McCain said in the speech.
The legislation, which never became law, would have moved oversight of Fannie and Freddie from the department of Housing and Urban Development to an independent Federal Housing Enterprise Regulatory Agency.
While it's impossible to know what the impact of his legislation would have been, the ad accurately describes McCain's stance and comments.