Naturally, as soon as they had money in their pockets, their behaviour did not improve.
"You had to watch them all the time," observed Jack Dawn, the make-up artist on the film.
But back in the Thirties, when the film was made, the outrage was in respect of the behaviour of the ‘little people’ (as they like to be called).
It was shocking simply because it was so unexpected.
Because they were so small, it was easy for other members of the cast to make the mistake of treating them like children.
Predictably, their reaction was to do everything they could to disabuse their colleagues of this notion."They were adults," recalled Jack Dawn firmly.
"They did not like us touching them or lifting them into their make-up chairs.
They insisted on climbing up by themselves." If the film-makers thought full-sized stars had attitude, they had seen nothing yet.
For although their antics on screen brought joy to generations of children, behind the scenes they astounded everyone with shocking episodes of drunkenness, depravity and wild sexual propositions from which no one was safe.
But Irvine Welsh’s new play, Babylon Heights, which premiered in San Francisco and is expected to open in London later this year, has already proved controversial because it has a bizarre twist.
The dwarves of the movie are being played by full-sized actors, who only appear small because the scenery is so huge - provoking protests from disability groups that the play is insulting and exploitative.
To the millions of fans of one of the most celebrated films of all time, The Wizard Of Oz, it sounds like an extraordinary project.
But the author of the cult book, Trainspotting, has written a new play about the Munchkins - the midgets who followed Judy Garland’s every step in the fictional land of Oz as she went on her adventures over the rainbow, meeting the Tin Man, the Scarecrow and the Cowardly Lion.