The name comes from a section of the United States tax code.
These organizations are not regulated by the Federal Election Commission. Therefore, people who would normally contribute millions of dollars to a candidate, could legally contribute to one of these groups instead.
"Swift Boat Veterans for Truth"
"Voices for Working Families"
"Americans for Progress and Opportunity"
"Laborers for Labrador Retreivers"
"Strippers for Subsidized Silicone"