Sporgery
Spam and forgery in one: drowning a newsgroup in posts bearing other people's names until the real conversation can no longer be found.
The word was coined around the floods that hit alt.religion.scientology in 1996–1997. Hundreds of thousands of meaningless posts went out with forged headers, often in the names of the group's own critics, so anyone searching for their writing got noise with their signature on it. The same group had earlier been hit with forged cancel messages; sporgery was the next step — rather than deleting speech, bury it.
It exploited the same weakness as spam and cancelbots: Usenet trusted the From line. The defences were killfiles, NoCeM notices and providers tracing where the flood came from. The method itself — flooding instead of censoring — has never gone out of fashion.