Wpbf.com reports: “Some dog walkers in downtown West Palm Beach [Florida] claim they have been attacked by a ‘crazy bird’ that swoops through the air.” The bird is described as being “black with a lot of yellow on its breast,” but its specific identity was not clear. To help identify the feathered nuisance, bird attack victim Ellen Levy made a composite sketch.
Although not quite to the standard of present-day ornithology, aided by blurred stills taken from the video, I think it might be a female yellow-headed blackbird (Xanthocephalus xanthocephalus). Any other suggestions from bird folks in the New World?
Update: several Old World ornithologists have identified the bird as a (female) Boat-tailed Grackle (Quiscalus major). These birds are indeed notorious dive-bombers.