That never crossed my mind. I'm still new to Torn technically after a little over 1 year of playing. I don't personally understand how that type of stuff works, and never will be interested in it due to not joining any factions that go to war.
As to your pertinent questions that I didn't answer...
1: How often do you actually find yourself looking at another players display case?
2: How often do you think people visit your display case?
3: What exactly do you own that you don't wish for other players to know about? And why?
1: I do from time to time look at display cases, not super often, but I do. Only because that is why they were created and sometimes I do find interesting things in display cases. I find it fun from time to time to do so.
2: Not sure. Although i am active in my faction, active in my company, active in DMs, active in the forums, etc. So by putting myself out there more than players that keep to themselves, statistically speaking, my profile page is more likely to be visited (and display case observed).
3: Nothing personally. Not that I can think of. However, Even though I personally don't have anything that I can think of, doesn't mean others don't have stuff they want to keep private. If this suggestion ever did get implemented, I would be a player that would utilize it, because why not?
Circling back to your comment on dirty bombs...
Torn City is a rough game. It isn't rainbows and butterflies. So if a suggestion like this were to be implemented in Torn and players were to utilize it for dirty bombs, what is your point? Players can send money anonymously and send mail anonymously, technically, Players mug other players, and are able to do so by hiding behind the name of "Someone" ... This game is full of gritty, crime-stylized gameplay that may not be fair to others. Am I personally going to use this type of suggestion from the initial post to hide dirty bombs? No. I don't ever see myself going that route in this game. I am more a laid back and in a faction that focuses on chains and OCs.
Overall, I think it is a cool idea because boxes in the inventory only allow x amount of items in it (a limit). What this player is suggesting is:
Is there anyway store items (That are never ment to be sold or used) away in once inventory? It could be like a cache or a boxs or maybe storage-unit for enhancers, tools and things that thje player knows he will be using later.
Which would be great with no limit.
All this being said, if this never came to light and Torn kept the inventory as is, with boxes, and display case.... i'm fine with that too.
I just think their idea is a good one, that's all.