adaliabooks: It depends. Someone randomly dropping codes in the forum probably doesn't care, and if the scammers kept to hoovering those up that would be bad enough. But it's when they then go on to use multiple accounts to enter giveaways and circumvent the rules of the giveaways so they can trade or sell on the keys (which is usually against the rules of the giveaways too). I doubt the donors are happy then.
Tauto: Yes,your right.Then Gog should control all giveaways and that would put a stop to that.
But GoG are never going to, short of banning gifts (which would be ridiculous and bad for business) there's no way they would intervene like that. They don't even have the resources to properly maintain the forum, why would they put effort into creating a giveaway system or policing the giveaways on the forum?
So we have to do it. The best we can with the tools available to us. And if that means stopping random drops to keep scammers away, and warning people when alt accounts are trying to hoover up the prizes in a giveaway, so be it.