Oyea, when my account got hacked i made a ticket and got this message back:
Originally Posted by Abstract
And then they closed my account. I told this to the owner of the website where i bought the game and they gave me a new cd-key...
Thank you for contacting Steam Support.
Your CD Keys purchased via storeis not sufficient proof of purchase for your account.
The sale and/or distribution of CD Keys for Valve products without the remainder of the retail packaged product (including all software, the media, the accompanying printed materials, and the license agreement) is not authorized by Valve, any of its agents, or by law.
Such activity violates the terms of the End User License Agreement ("EULA") for Valve products and thus infringes upon Valve’s copyrights in its software.