Neighbors can be volatile when approached, and many don't seem to care whatsoever how their lighting affects others, even when alternative light solutions are suggested and offered to them free. What about affected citizens compiling a central database of properties on the web or even Facebook, that the city could then check out and issue citations where appropriate? There are quite a few newer fixture styles with LED lights completely concealed above while lighting the area below.  As I recall, Lowe's has a good selection. There's simply no excuse for this type of light pollution/trespass.