actually, from what i've seen, heard, and read about pirating in general, the best (or at least most effective) way to dissuade pirates is really more a matter of engagement and
not hiding a product behind DRMs- and especially ultra-restrictive and even potentially dangerous DRMs like secuROM which have become infamous. overall, they actually encourage piracy and once one hacker cracks the DRM and uploads it, it's back to square one.
not too long ago i bought Democracy 3 (Positech games AKA Cliff "cliffski" Harris) and when i went to the positech website looking for D3 mods. among all the things i expected to see from a developer website, i saw something i certainly DIDN'T expect, which lead me to this:
http://www.positech.co.uk/talkingtopirates.html
i have to say, when cliffski actually asked on various blogs "do you pirate my games? and if so, why?" he probably did more to shed light on the phenomenon of internet piracy than anyone else ever. seriously, read his article, it really is amazing.