"Pig" was a non-conformists' name for a member or especially a representative of "The Establishment" during the sixties. As time passed, the most evident of those representatives were the ones who took us to jail for gathering peacefully in protest of various causes. In other words, the police were called "pigs." That definition has stuck fairly well over the years.
Many "purists" still use the older meaning; anyone bought and sold to make a buck or two AND by doing so, supported the "Establishment" which was in question way back then, much as it still is to this day. (I had to go to the pigs - bankers - when I refinanced my house a few years ago to take advantage of the extremely low interest rates. I might be a pig?!?
) The definition of "establishment" has evolved over the years, but I can still call "PIG" when I see it.
I was making a joke about how ready you are to get this thread to more reflect the title post. I called you a thread pig!
You bloody copper!