I don't know much about hacking - on account of the fact that I don't see the appeal of it. I'm not brilliant at FPS but having fun is why I play... And as I tune into a game, I get better at it anyway, and that makes it more fun.
....But this article sounds like a load of balls.
What I know about modern online games is that developers learned some time ago not to have the server send information to the client that it doesn't need.
If BF3 is sending all player data to every player regardless of whether they're visible or not then yeah, dumb - and hack able client-side. The server decides what you can and can't do and merely informs the client - PS1 being the last example of client side decision making I heard of with its hit detection.
If it isn't sending that information to your computer then nothing you can install is gonna allow you to see it. You'd need to hack the server.... and whoever heard of people hacking Sony's servers? What a ridiculous notion
:sarcasm:
With that in mind - afaik, a client-side hack could only make you better (maybe faster or more accurate mouse movements) within the context of what the game allows. Kill everyone on the map by pressing a button? do me a favour....!