The Jargon File (version 4.4.7, 29 Dec 2003):

Internet Death Penalty


    [Usenet] (often abbreviated IDP) The ultimate sanction against spam
    -emitting sites ? complete shunning at the router level of all mail and
    packets, as well as Usenet messages, from the offending domain(s). Compare
    Usenet Death Penalty, with which it is sometimes confused.