Final answer:
The provided references do not link to any information about illegal activities undertaken by Absolom and Matthew Kumalo; thus, an accurate answer cannot be given without additional context.
Step-by-step explanation:
The question appears to be asking about illegal activities of characters named Absolom and Matthew Kumalo, but there is no context in the provided references that links these names to any specific illegal act. The historical accounts presented include the battle in the forest of Ephraim and Joab's men murdering Absalom from the Bible, as well as the testimony of Abram Colby about the violence of the Ku Klux Klan. However, these references do not provide relevant information to Absolom and Matthew Kumalo's illegal actions. Without further context from the work of literature, or non-literary sources that these characters are from, it is not possible to provide an accurate answer regarding their illegal activities.