A:Â We created the account linking to make it easy for you to access your steam games. We don’t store your username or password when you sign into Steam from the download page. The connection we make will only grant access for Humble to redeem Steam keys on your account. To remove the connection after redeeming your purchases, you can click unlink your account right from the same download page where you linked them in the first place.
Q:Â Why the change?
A:Â The new Steam key redemption process will make it even easier to quickly redeem your games on Steam! One click and the games will appear instantly in your library!
Q:Â How do I redeem my Steam keys?
A:Â When you click on a Steam key for the first time you will be walked through a process of linking your Steam account to your Humble Bundle account or download page. Once you have completed this process you will never have to do it again! When you click on the button for your Steam key, the game will automatically be redeemed to your account with just one click!
This apparently comes as a response to the rampant abuse of Humble Bundle purchases to acquire titles for lower costs and then resale them with a premium for individual titles. No other change has been announced for direct download, Origin or other DRMs.