No, we do not remove items from a user's inventory or data as a consequence of a ban. Your items remain stationed in your backpack, even if your account is permanently banned. As we offer users the ability to appeal their bans, especially in cases where the ban was found to be a mistake on our part, it would be extremely unfair for them to return to the game with nothing in their inventory.
We may remove items from your inventory at our discretion, mostly in cases where the reason for the ban is that items were obtained illegitimately, such as duplication or exploting. We will do our best to notify you of this if this happens to you, such as letting you know when you appeal your ban.