Before the Pearl Harbor attack, part of Japan's plan was to send tourists to Hawaii to map out where the battleship berths were, where the airfields were etc. etc. and know the whole military layout. From this and other means they were able to build a mock copy of Pearl Harbor and so plan how to attack and do the most damage. Obviously they were successful.
Guess what? Just recently several Chinese tourists (one of Ma's supposed ways of boosting the economy) were caught and expelled from Hualien Air Force Base during a military show. Many of Taiwan's weapons systems were on display at the base which was open to the Taiwanese public, but not to Chinese tourists. And believe it or not, the Chinese tourists were taking pictures, surprise, surprise. I guess all tourists go to a country to check out their air bases.