My 5 cents...
1 - my copy is legitimate
2 - I personnaly do not like games where you need the cd to play (noise, wher's the cd ?, ...)
3 - as has been said, wargamers are usually more mature than the average computer gamer, which coupled with the DIF game type (not a FPS or RTS), I guess that most of the pirates either won't stay long or will get converted to playing that kind of games... which on the long term might be better for us all !
So IMHO it now seems too late to fight the original DIF pirates, and they probably have brought some new blood into our kind of games; i suggest we accept that, even (and i'm sorry for you designers and workers about that) if it means money losses, and capitalize about extensions, tournaments and so on (with ways to let most pirates out) to create a living game that rewards its designers.
Whatever we do, there' ll always be pirates...