Some Steam users have discovered that their Sniper Elite III keys aren't working. This is because a number of keys for the game were stolen and then resold to other vendors.
Affected users are being offered the Target Hitler DLC as compensation but, oddly, not replacement keys, so they can't actually play it at present. They've been told they need to contact the reseller directly requesting a refund instead. Rebellion are adamant it's not their fault, and so apparently they won't do anything about it:
"One of our PC retail distributors informed us that some of their allotted Steam keys were stolen. We believe these keys were then resold to multiple companies, with no payments going to either Valve or the retail distributor.
All we can suggest if you have been affected is to please contact your vendor and first ask for a replacement key, and then contact us for the free pre-order DLC if you are successful."