Some call Joseph Piacentile a hero. Over the last 15 years, the New Jersey physician has been a whistle-blower in antifraud lawsuits that have returned more than $1 billion to the U.S. Treasury.

His weapon has been the False Claims Act, whose qui tam provisions allow private citizens to sue–on behalf of the government–companies, or individuals that falsely or fraudulently claim federal funds. Originally enacted during the Civil War, the FCA was amended in 1986 to give prospective plaintiffs and government prosecutors more powerful incentives to pursue fraud. Defendants became liable for treble damages (plus a civil penalty for each false claim), and plaintiffs, known as relators, would get 15 – 30 percent of the government’s recovery and full attorneys’ fees. Since the 1986 amendments, the United States has recovered more than $24 billion in False Claims Act cases, including $15.7 billion from lawsuits filed by private citizens.