Crapflooding is a form of trolling discussion sites such as Slashdot with nonsensical, inane, or repetitive postings in order to make it difficult for other users to read other postings.
It is also motivated by a desire to waste the host site's bandwidth and storage space with useless text, however it is typically considered, by other trolls, to be a "lesser" form of trolling as little effort is involved.