And how, Mr. Erik, do you propose nintendo create this magic filter?
A pokemon is determined by a rather small number of variables that can easily be determined and changed within legal limits.
So, as I've said several times already, if a pokemon is hacked within legal limits, and if it doesnt cause your game to explode, there is absolutely no way for Nintendo or anyone else to be able to tell the difference between a hacked pokemon or a legit one.
They tried foiling hackers with deoxys and mew: they created an obedience code that would screw up those monsters if they were sharked.
But guess what? The hacking community figured out how to modify that one too!
You can't stop the hackers no matter how hard you try. Accept it.
The dangerous ones are the really bad hackers: they create the pokemon that screw up the game.