Through using this URL, it’s easily possible to view any group or player’s inventory of meshes, models, decals and plugins even when they are not for sale, and the player has their inventory hidden.
You can also achieve this by just entering their name into the box on the bottom left, and selecting show unavailable items.
This makes hiding your inventory practically useless, as I really don’t care if people are able to see what catalog items I own, I just don’t want people stealing my assets.