well, I'm guessing that if the software is not legally yours, it follows that you are not permitted to sell it.
you merely purchase the right to use the software, and i think that's non-transferable.
well that's the impression i get from the eula anyway - i'm not a legal expert and there might be consumer rights that supersede this and allow the sale of the license.
anyways, it does seem like this system of online actiation where the cd-key is checked and then perminantly associated with an account (a bit like steam on a game by game basis) is designed more to combat the 2nd hand market than the pirates.
there's a lot of games where this applies now i think- mass effect , far cry 2, spore - a lot of Ubi and EA stuff basically.
Unless you also recieve the account information a second hand copy is useless.
however some games are less harsh with only the mp componant affected.
I was wondering if this was the case with Ubi's World in conflict?
I'm pretty sure that, like supreme commander, online mp will be unavailable if the copy has already been regestered to an account (and you don't have the details)