From the experiences I've had on Van Isle rivers, about every 2nd or 3rd hook I catch when I snag the bottom (OK, so I end up catching more gear these days than fish) is still barbed! Do that many guys not know about the barbless hook rule? I think not. I think they choose to keep the barb wide open, that way they can drag the fish to shore by its butt with more efficiency.
Education is a good tool. The Salmon supplement and the Freshwater guides have all the info you need. People just need to read it.
I do agree that it is up to us to "wise-up" the guys doing it wrong. If you're not huge though you need to be careful, because, as a species, the "fridge fisherman" is easily riled up and prone to anger ... even attack if you're on the Vedder.
One last note though, there are actual newbies out there that are simply making a mistake. A quick "hey, did you know we're only allowed to use ... or whatever" is all they need to clean up their act.
Try being helpful first, who knows, you might make a friend. Its always helpful to have a friend when fishing ... preferably someone who runs slower than you if you meet a bear.
Cheers,
Alex
... "high water" is when you can fish from your car.