This is not the image I was looking for, but it will do.
Back in the day; I vividly recall looking at a marketing image of classic ELITE showing a large and disparate armada of traders lining up to dock at a station. The image captured the moment a player had exploded one of those traders to gain cargo.
I remember looking at that image in Acorn Magazine or something like it and thinking that it was so cool and that someone should program a game where there could be players for each of those individual ships.
Well someone did, CCP has stated that much of the inspiration for EVE came from classic ELITE.
So to answer your question: When did High SEC ganking start? At the drawing board. It is a founding principle.
The reason I am commenting here is because I will not stand by idly and see that principle corrupted.
So when you and I lose our s**t , try to remember, we are living the dream.