What this means is that you cannot run modded versions of the game, like something with low gravity, or no reload, or all crits. Or with custom maps.
The good part is that it makes it harder to run hacks.

But I dont think thats worth not having dedicated servers.

public class Singleton{

private static final int example = 0; //static variable declared just for example

private Singleton(){ }

public static Singleton getInstance() {

return SingletonHolder.instance;
}

private static class SingletonHolder {
static final Singleton instance = new Singleton();
}

Thanks for your response.

The advantage for initialize-on-demand idiom is that the static variable is inside an inner class. The main Singleton class does not contain any static variables so eager instantiation will not take place.

I personally have not seen anyone trying to hack their own singletons on purpose. Why go through the trouble of creating a singleton only to hack it into multiple instances? Might as well just create a regular class in the first place.

So that article is not really a contradiction of thread-safe methods for creating singletons. The methods listed here are still thread-safe methods of creating a singleton. But it does not prevent you from using reflection to hack the singleton into multiple instances.

http://yohanliyanage.blogspot.com/2009/09/breaking-singleton.html