Valve has locked all loot boxes for Counter-Strike: Global Offensive players in Netherlands and Belgium.
The change was implemented in a CS:GO patch this week. In addition to numerous other changes, the final "Misc" section of the patch notes contained, "Updated Steam and CS:GO account restrictions for users in Netherlands and Belgium."
The first point is that Steam Trading and Steam Market features are available again to Steam users in the Netherlands. Valve disabled item trading in June, in response to the threat of prosecution from the Dutch Gaming Authority.
At the time, Valve said it hoped that, "after more engagement with the [Dutch Gaming Authority], they may refine their legal demands so that we can find a solution that is less inconvenient."
That much appears to have happened for item trading, but loot boxes are another matter. The second point in the patch notes said that "customers in Netherlands and Belgium will be restricted from opening containers" in CS:GO.