Through a wormhole, darkly: The Light of Other Days

 The Light of Other Days by Arthur C. Clarke and Stephen Baxter. 

This novel, one of Clarke's last (though I think it's safe to assume that Baxter did most of the actual writing), explores the cultural and psychological impact of visual wormhole technology that allows viewers to see what's going on anywhere on Earth... and, eventually, anywhere in the universe, at any time. This is an idea that comes up, briefly, in Clarke's masterpiece, Childhood's End, where the alien Overlords introduce...