Len, that guy also left himself open for a huge lawsuit. If any of the anglers had any injuries there are lawyers out there who would take that case for a cut of the award. That is just plain dumb.
That said in Georgia, as I understand it, I have not looked up the statue, if you own the land on each side of a stream you own the water and can prevent anyone from floating, wading, etc. in the stream. There was a case where a landowner shot a guy in a boat and got away with it.
It's easier to fool people than to convince them that they have been fooled. Mark Twain