Exploited List Question

They were either given away for free, or a bunch of keys were leaked due to a glitch.

I don't know all the reasons, but I will try to answer the ones I know:

• Serious Sam: Double D
  0 USD payment exploit on getgames

• Dead Island
  Steam Keys were hacked/leaked

• Portal 2
  Steam Keys were hacked/leaked

• Puppy Games Keys
  Free games given away on the developer's birthday by the developer. some people have taken more than the allowed 1 (and the 1 was for personal use only!) some of the exploited keys have already been revoked, see the puppygames blog for more information.

• Dark Messiah of Might & Magic Multiplayer
  (was) free on a polish gaming site

• Eets (in certain amounts)
  iPhone app exploit

• Puzzle Agent (same reason as Eets)

The fact that they are forbidden here does not mean you can still get any of them for free.

You should not try to obtain exploited game keys, because many have already been revoked by Steam, others might get revoked in the future.

If they are forbidden, why not remove them from the giveaway game list?

Thanks for the explanations!