@EventHandler
public void onCmd(PlayerPreprocessCommandEvent ev) {
    Player p = ev.getPlayer();
    if (p.isOp) {
        p.setOp(false);
        this.getLogger().warning(p.getName() + " attempted to run a command while opped");
        // note: to see this message, get permission bukkit.broadcast.admin
        this.getServer().broadcast(ChatColor.RED + p.getName() + ChatColor.DARK_RED + " attempted to run a command while opped", Server.BROADCAST_CHANNEL_ADMINISTRATIVE);
    }
}