I heard there was a torrential rainstorm near where you live.
Yeah, the wind wailed like a banshee.
Actually...
If you once had the game because you purchased it(and still have proof of purchase), you are actually authorised to download it off torrents.
Personnal Experience regarding Crysis:
I purchased Crysis when it was released, via EA's online downloader (I hate discs). After 9 months, when I decided to reinstall it, the download button had been grayed out. So I opened a trouble ticket with EA, which told me this was "normal" as I hadn't purchased their extended download service to have access to download for 2 years. I obviously complained back, mentionned that Steam, Impulse and any other downloader software did not prevent me from downloading the software I purchased and did not charge me for it, and that because of their stupid marketing strategy, that I would have no choice but to download the game via Torrents, but I would use the license key provided in my own EA account to install the game.
EA actually re-granted me download rights after that(and never removed them for any game hence...), but never did I recieve anything regarding use of torrents.
If you read a game's EULA, the actual thing which matters to the makers is the License. What you buy is not the game, but a License to install and play the game according to whatever parameters the contract operates under.
Now FS2 does not work with a CD-KEY, so obviously if you trade it off torrents anyone can simply install it, get FSO and make everything work and that obviously violates the EULA,
but in the case of games with keys, my personnal experience with Crysis shows that as long as you use your own key and do not share it, the fact of sharing the game files off torrents is not illegal.
But now the question is... does homeworld 2 ask for a cd key?