On Usenet, the Usenet Death Penalty (or UDP) is a final penalty that may be issued against Internet service providers or single users who produce too much spam. Messages that fall under the jurisdiction of a Usenet Death Penalty will be cancelled.

There are three types of Usenet Death Penalty:

1. Active: with an active UDP, messages that fall under the UDP will be automatically cancelled by third parties or their agents.
2. Passive: with a passive UDP, messages that fall under the UDP will simply be ignored and will not spread.
3. Partial: a partial UDP applies only to a certain subset of newsgroups, not the entire Usenet newsgroup hierarchy.

To be effective, the UDP must be supported by a large number of servers, or the majority of the major transit servers. Otherwise, the articles will propagate throught the smaller, slower peerings.

UDPs are not casual acts. They are announced before hand, only after the owner of the offending server has been contacted and given several chances to correct the perceived problem.

Since the effects on the users of a server under a UDP can be significant, if they want to post, UDPs have a tendency to get the problem corrected in a short period of time.