None of the players can kick or ban players. The servers have a MODERN TK system. You can only get banned by your own will, having accumulated 5000 TK, but you need to harm players CONSTANTLY.
Players up to 5000 rank points cannot harm other players at all, but they receive TK.
More details about the TK/PvP/PK system are written here: https://steamcommunity.com/groups/l4d2badblood/discussions/3/737036097948944868/