It's a bit of a minefield!
As far as the RIL is concerned, the photographer retains copyright and allows us to use them as inspiration
Over in the UK here, since 9:11, it has sometimes been an offence to take photos in public places such as Malls - because sometimes 'the watchers' perceive a threat ........ you may be taking photos for terrorist activities!
...... thankfully, common sense seems to apply these days.
But, I have also read of owners being precious about others photographing their properties, presumably for similar reasons so I suppose it would be better then, if possible, to ask permission!