Usual penalties include banning, either permanent or temporary, or an admin using a slay command to kill the guilty party. This can vary from situation to situation and are often defined by the servers. This was never an official term but was fan made.
Random Deathmatch (abbreviated to 'RDM') is a term used to denote when a player randomly kills other players without valid reasons or when someone is upset that they died, even for a legitimate reason.