The bots on the good camping sites are insane, it's clearly a few people who have figured it out. Some even sell alerting services. Keep in mind, in some places, there aren't any other options, looking at the most commonly watched ones they are in very unique places like the Florida Keys. They get resold on the secondary market or you pay someone a premium upfront to bot the reservation for you. Call the parks, they will acknowledge it (or did to me), it's also obvious when all spots are booked in milliseconds.