Java SE 7 Spec (http://docs.oracle.com/javase/7/docs/api/), java.util.ServiceLoader<S> section says:
"Unless otherwise specified, passing a null argument to any method in this class will cause a NullPointerException to be thrown."

According to the Spec, the statement ServiceLoader.load(null) should throw an NPE.
But actually it throws nothing, as can be checked by the following simple test:

public class Test {
  public static void main(String[] args) {
    try {
        java.util.ServiceLoader.load(null);
        System.out.println("Failed: NPE is not thrown");
    } catch (NullPointerException e) {
        System.out.println("OK");
    }
  }
}