Just adding my experience to the discussion. Im in advertising and sometimes we have to recce for locations for filming. Recently I was taking photos of colonial houses at Sembawang and was detained by a police patrol which grew from 1 car to 3 cars and 2 officers to 6 officers. They questioned me, checked on whether I had a criminal record, called my boss to verify my identity etc etc. Generally a whole deal of hassle. And when I asked them.... "errr what did I do? Im just taking photos of some nice colonial houses nothing sensitive like a army base or something.... "Then they told me these house happened to be rented by US servicemen when they stop over at Sembawang Airbase or Naval Base. I was like "Sorry sir I didnt know." The reply was "you are not supposed to know"
In the end they let me off after I deleted all the photos I took..... haizzzz