The Anti-Pinkerton Act was a law passed by the U.S. Congress in 1893 to limit the federal government's ability to hire private investigators or mercenaries. The Anti-Pinkerton Act is contained within 5 U.S.C. 3108 and purports to specifically restrict the government of the United States (as well as that of the District of Columbia) from hiring employees of Pinkerton or similar organizations. In actuality, the United States government is a significant customer of private security services, and has made use of private military contractors in the past.