Every year this topic repeats itself, and sadly, things are far worse today than they were five or ten years ago.
As a result, I am starting to highly doubt the effectiveness of this and other fishing forums in deterring the behavior you witnessed.
I have chosen to stay away from the river until water comes up and many more miles of fishable water become available. As it is, fish are concentrated in a very limited number of deeper sections during the day, making them an easy target for the unscrupulous.
I never thought I would say this during salmon season, but given the rampant increase in questionable individuals on the river these days, interior lakes with their big trout sound like a much more gratifying alternative.
Short of a huge increase in enforcement (which won't happen because fish snagging is very low on the Govt's scale of priorities), the only solution I see to this situation is to close the river to all retention at least until the rains bring the water levels up. Without a legal option to keep fish, at least 90% of the snaggers would stay home.