From The Register:
sounds like an urban legend to me.
You'd be suprised! Back when the Joint Strike Fighter (JSF) was still in the planning stage and was Top Secret stuff in a national security sense, an MI5 agent lost his laptop with incerdibly sensitive Top Secret plans for the project on it. Said 'secret' agent thought he'd try to recover the machine by placing an advert in the local newspaper. The machine turned up a short time later at a desk in a tabloid newspaper office. (The Sun, if I can remember correctly).
Stranger things have happened!
That sort of thing happens all the time. Company and organisational laptops are a very big security risk.
I'm a staff sergeant in the US Army - wouldn't surprise me - heck I've seen all kind of stuff thrown out in the trash.
But Top secret stuff usually is destroyed properly.