We have seen a large increase in contacts where people had their games removed or disabled on their Steam accounts on the request of Paradox Interactive. When this happens, it is with almost certainly because the code was purchased from a lesser known website or online auction for a low price. Sadly, this is a common scam technique as the initial purchase was made with stolen or fake credit cards. Once it comes to our knowledge that we did not receive payment for a code, we ask Steam to disable it. This can sometimes take up to a few weeks, and thus makes no sense in the eye of the player.
Be mindful and look up a seller before giving them your money! (A simple google search might reveal a lot)
Be suspicious of people who are able to sell things way below market price. There are (sadly) not many people out there distributing games and goods out of the good of their heart.
We see an increased number of victims of scams like this. So please be careful!