Hit from behind is a classic blunder. Almost always, it means the other driver was following too closely or not paying attention. Since all of these accidents

Hit from behind is a classic blunder. Almost always, it means the other driver was following too closely or not paying attention. Since all of these accidents happened in the US, is the driver that hits from behind normally responsible for the accident? (For a moment, let's exclude predatory behavior where the front driver is doing something toxic, like intentionally pump-breaking on a high speed road to induce a hit-from-behind accident.)