or as many people here probably does (though they problably won't admit it, i'm one of those people) uses warez-sites for everything
Thats trouble waiting to happen for many other reasons besides the theft aspect.
At least with Steam, EA, or whatever platform you choose you are getting the real game.
That can not be said for pirated games or software for that matter.
You have no clue what has actually been changed, removed, or added to the files.
Majority of the time you also get "Bonus Gifts" this way as well, although it does not always seem apparent.
Not to mention, I can not count the times Ive attempted to help someone with a odd game issue, only to find it was a pirated copy.
Buy a legit copy, Problem Solved.
Argue all you want, that its harmless, but we all know that is not the case.
Besides, none of them (Steam, EA etc) take any noticable resources to run in the first place.