Abbreviated UDP, a Usenet penalty enforced by system administrators of an ISP or NSP against other service providers. Usenet is by nature cooperative, and the UDP is one way that administrators can handle uncooperative members. UDPs are typically issued to ISP/NSPs that have users that are spamming and that have not stopped the users from doing so even after repeated requests for the administrators to deal with the spam. When a UDP is issued, any messages posted to Usenet from that site will be cancelled. UDPs are also issued to individual spammers.