UPDATE: Specific listings can be made stealth now as well. From the Seller's Guide:
When listing or editing an item, you may also control its visibility. By checking the box next to stealth listing, you remove the listing from public searches, browsing, and even your user page, so it is only accessible by visiting the item url directly (you can find a link on your account page). This is useful for custom listings meant only for a specific buyer, or for listings you don't want visible on your publicly facing user page.
There are heroes among us here at Silk Road. Every day they risk their lives, fortunes, and precious liberty for us. They are on the front lines making tough decisions and working their asses off to make this market what it is. Of course I am talking about our vendors. I won't try to acknowledge them individually because we are blessed with so many extraordinary people who have stepped up to the task and taken it upon themselves to find a way to stock the shelves at Silk Road. They labor tirelessly to balance the heavy responsibilities they've taken on. From customer support, to supply chain and inventory management, to promotion, to quality control, to risk management and mitigation, to IT, to Bitcoin finance, to order fulfillment, and on and on, these guys and gals are professionals that are rising to the top of their game.
Often, when another superstar vendor joins our ranks, they rise quickly toward the top of the heap. They are amazed by the demand for their products and service, but also troubled by the attention they've gained. They risk so much already and being in the spotlight, while good for business, also poses the risk of becoming a target for law enforcement.
At the request of some of our top vendors, we are implementing a new feature called Stealth Mode. From the Seller's Guide:
Stealth mode allows you to run your business out of view of the general public. Whether your sales are growing faster than you can expand your infrastructure to keep up, or you just don't want to be in the public eye any more and are happy with the size of your current customer base, stealth mode might by the solution for you. When activated, your listings will no longer appear in public searches, category views, or any pages linked to from the public site. However, your user and item pages will still be available when accessed directly, so your regular customers can still make purchases from you. Just make sure they have your userpage url. Note: It can take up to an hour for your listings to go stealth because of caching.
Our aim is to give our vendors the ability to control the growth rate and visibility of their businesses and take on the level of risk they are comfortable with.
Here's to our heroes! Cheers!
Update: after reading your responses, I realized one of the main reasons for going stealth would be to hide the size and scope of your operation. So, some data has been removed from a vendor's user and item pages when in stealth mode.