Potentially Dangerous Taxpayer (PDT)[1] is a government designation assigned by the Internal Revenue Service (IRS) to taxpayers of the United States of America whom IRS officials claim have demonstrated a capacity for violence against employees of the IRS or other government agencies, contractors or their families.
[2][3] Suspected PDT cases are handled by the Treasury Inspector General for Tax Administration.
[6][7] Mark Pitcavage of the Anti-Defamation League called Stack a lone-wolf "homegrown, self-taught extremist" with possible ties to the Tax Protest Movement.
[8] This is a chart from an IRS report that shows data on quantities:[9] ‡ 2012 is only up until July 2012 In 2009, Randy Nowak of Mulberry, Florida, was convicted and sentenced to 30 years in prison for attempting to hire a hitman to murder the IRS agent doing his audit.
[10] In other cases, disgruntled taxpayers have enclosed foreign objects with their returns.