If someone gets your URL they can take your Steam Codes, they can even claim your pages thus not even allowing you to download the DRM free one. 

That seems like a massive security hole. Is it by design or wtf?

well, he still can access the games he bought, as with humble bundle you get a drm free version (only exception I know is the new Sid Meiers bundle) you can download from the website you receive once you paid

but he can't add the games to his steam account as the steam keys have already been used by somebody else

@ OP)

Personally I never claimed my Steam keys for Humble Bundle #1 and #2, but they were still there (well, now I claimed them). Maybe somebody hacked your email account?

I would guess someone out there is using a brute force script on redemption URLs and selling keys off to key sales sites.

UPDATE:

Charles, the Humble Bundle "support ninja", has reset ALL of my compromised transactions, resulting in me being able to recover all 49 games.

EVERY. SINGLE. ONE.

I have since basically immediately redeemed them all to my Steam account (resulting in my account now reading that I've only played 17% of my total 308 game collection, hahaha).

Glad to hear it turned out well. Software theft can be the most annoying, rage inducing thing in the world.

Indeed.
Glad it all turned out alright.

That is pretty cool and hopefully now those guys who are giving the robbers + rating as great traders for selling stolen games will be in for a nasty shock when their games no longer work.

Stay safe btw, was not aware there was someone on Vgchartz playing real Modern Warfare for us :)

Thanks Obama

- edit.

I may or may not have clicked reply on the wrong thread!

I'm sure Obama would slap the shit outta someone if he knew they stole property from someone in the US military.