Sometimes heavily populated cities have seen a large amount of UFO activity. There was a story about the Phoenix lights which still hasn't been adequately explained, and Mexico city is also a big hot spot. I'm not saying it's aliens, but I do think there are things that maybe we don't understand going on. Personally I think some of it has to do with demonic activity but most of it has to do with normal stuff that's misidentified like airplanes or sattelites.