Is Quantum Mechanics Non-local?

Stapp has recently argued from a version of the Hardy type experiments that quantum mechanics must be non-local, independent of any additional assumptions like realism or hidden variables. I argue that his argument does include an additional assumption about the reality of certain counter-factual statements. In a recent paper [1] H. Stapp has argued that quantum mechanics is non-local. He bases this conclusion on a weak definition of locality for a physical theory and an examination of the predictions of quantum mechanics for a specific two particle Hardy-type [2] [3] experiment. It was already known since the 50's from the theorem of J.S. Bell [4] that quantum mechanics violated the correlations expected in any theory which is both local and is " hidden variable " theory, in which the statistics arises out of the lack of knowledge of the values of local hidden variables which determine the outcome of the experiment itself. However, Stapp's argument claims to strengthen that conclusion by arguing that no local theory cannot give the same predictions as quantum mechanics. Ie, he reaches the conclusion that quantum mechanics is non-local. In his paper, Stapp claims that his proof that Quantum mechanics is non-local applies only if one assumes that locality holds in all frames of a special relativistic system. However I will take this as a given, that locality is to be taken to apply to any two systems when 1