Reuters reporters James Pomfret and Kelvin Soh have written a piece about the security measures Apple suppliers use to reduce the likelihood of leaks, you can read the five-page piece over here. Foxconn takes this very seriously, workers at the company's Longhua manufacturing plant live inside a walled city, and are provided with most of their daily needs so they have little reason to venture outside, which reduces the likelihood of leaks.
Inside the walled city -- one of several compounds run by Foxconn International, a major supplier for Apple Inc -- employees are provided with most of their daily needs. There are dormitories, canteens, recreation facilities, even banks, post offices and bakeries.
The rank-and-file within the compound have little reason to venture outside. That reduces the likelihood of leaks, which in turn lessens the risk of incurring the wrath of Apple and its chief executive, Steve Jobs, whose product launches have turned into long-running, tightly controlled media spectacles.