What Does Usenet Death Penalty (UDP) Mean?
The Usenet Death Penalty (UDP) is a penalty for non-adherence to Usenet anti-spam standards. This penalty is considered the final straw for ISPs or individual users who have received serious prior warnings.
Techopedia Explains Usenet Death Penalty (UDP)
This term is somewhat dated given the relative decline in popularity of Usenet. In the early 90s this was a major issue as Usenet users got together in order to get the attention of unresponsive ISPs.
At one point is was big news that an ISP like Excite@Home or CompuServe was hit with a Usenet death penalty. While still used, this is clearly less of an issue today as compared to the simplistic systems of the early Web.