A flood means posting a big amount of messages to a Newsgroup in a short
period of time. While flooding is sometimes seen as netabuse (i.e. when a
person tries to make a Newsgroup unreadable with it), it is often very
welcome in binary Newsgroups, where it usually means that a bigger number of
pics is being posted. Too much floods in a too short time are not good as
the new ones push the old ones off the server.