CS:GO announced that any container key purchased in-game is no longer going to be allowed to leave the purchasing account. What this means is that these keys can no longer be traded or even sold on the Steam Community Market. Valve did say that any pre-existing CS:GO container keys are going to be unaffected by this update. This means that only these keys can still be sold or traded.
If you're not familiar, container keys are items that can be bought using real money and then used to unlock what can be considered as CS:GO's equivalent to loot boxes. So, why this change? According to Valve, the company has been observing key trades and most of them were for legitimate customers.
However, Valve went on to say that it looked as if worldwide fraud networks made use of CS:GO keys in order to liquidate their gains, adding that it came to a point that almost "all key purchases that end up being traded or sold on the marketplace are believed to be fraud-sourced." If that looks to be too technical, what Valve is saying is that the container keys were being used for money laundering. This is the reason why, according to Valve, newly purchased keys are not going to be " tradeable or marketable."
That there is fraud present is not that at all surprising, especially if one knows about keys. Aside from opening containers, keys were also used as a sort of currency when it came to skin trading for CS:GO. It came to a point that some players would trade skins for keys and vice-versa.
Generally, it shouldn't have much of an impact to a majority of CS:GO users who purchase keys in order to open containers. Players can still buy keys to open containers in their inventory. The only difference is that the keys can no longer be traded, or even transacted, through the Steam Community Market.
However, this change could impact some of the legitimate users. For Valve, fighting fraud is an issue that they continue to prioritize across Steam and their products.
For users who want to give feedback or air concerns with regards to this change can email Valve here using the subject "Key Restriction."
