They could at least inform customers about the censorship and not sweep it under the rug:
> among all of the restricted products identified by this study, none presented a message to the user explaining that the items were unavailable due to regulatory reasons. Instead, each item was communicated as either being “currently unavailable”, “temporarily out of stock”, or that “this item cannot be shipped to your selected delivery location”.
Unfortunately, the government sometimes bans disclosing this. The US government, for instance, bans the telcos from telling the customers that they're being tapped.
> among all of the restricted products identified by this study, none presented a message to the user explaining that the items were unavailable due to regulatory reasons. Instead, each item was communicated as either being “currently unavailable”, “temporarily out of stock”, or that “this item cannot be shipped to your selected delivery location”.