When a player joins the server and Mass RDMs (kills 3 or more people), then leaves to avoids punishment.
If multiple players are found ghosting, with sufficient evidence.
If a ban request is approved through the forums.
When someone has too many recent warnings (preferably after getting a verbal warning first).
When a player continuously Mass RDMs, three or more times, cleary showing that he's not willing to cooperate after the multiple slays and warns.