Number of Federal PACs Increases
http://www.fec.gov/press/press2009/20090309PACcount.shtml
Press release which reports that the number of federally registered political action committees increased by 9% from 4,234 on January 1, 2008 to 4,611 on January 1, 2009. Provides counts of PACs by type of sponsor since 1974. From the Federal Election Commission.