I own this DLC already but I can still join this giveaway, not much you can do to really check if the winner doesn't actually own it though, which sucks...

I wish there was a better way to track DLC on Steam accounts, but sadly, there isn't.

I won't be joining and I hope anyone else who owns it is just as honorable.

Word is that this DLC is free, at the moment, which means this giveaway falls under the "free and exploited games" clause mentioned in the site rules. If this turns out to be true, expect this giveaway to be deleted.