Originally Posted by exerda
Not a "TSA person," but my understanding--unless procedures have changed--is that you may always request that all of your property (including but not limited to laptops) remain visible to you at all times during a secondary screening or an inspection of that property. It's in the TSA's best interests to do so to prevent claims of theft, damage, etc.
From the TSA website:
While you will be separated from your carry-on baggage during this process, every effort will be made to help you maintain visual contact with your carry-ons.
Operative words: "every effort" - no guarantee