The Knights of the Eastern Calculus (often the Knights) is a group of pseudonymous, notorious and highly-skilled computer crackers.
They interact with Lain in various ways, possibly trying to trick her into entering The Wired or join them. They use Taro to get to her. In some way, they are responsible for the use and distribution of the psyche chip, which somehow massively improves network performance despite being a CPU. Other technologies they are suspected of creating and/or distributing include KIDS and accela.