I know these days all the Copy DVDS u buy have usually been done by a Camcorder in the Cinema or in the case of the really good Quality Ones they have been copied off the Digital Cinema reels. So in the early 80s when you were lucky enough to get Pirate copys of E.T, First Blood, Return of the Jedi etc where did they originate from? sureley the Camcorders of those times would have been way too large and heavy to smuggle into the Cinemas,plus i never remember hearing Audiences either, sorry just something i was thinking about ;)
most dvd copies are done from region 1 dvds (released long before they get released here) on home computers using software to break the encryption, hence a lot of the really good copies you talk about.
In the 80's, the same thing happened - a video was released months or years in the US ahead of the UK, allowing ample time for copies to be imported.