I've actually seen one once... In a minor institution in Denmark called Hobro Mini Zoo (a very small zoo like American roadside zoos). They kept one in an aviary, and since I've been very interested in birds all my life, I could easily identify this rare bird. It was in September 2004, and when I returned next month it was gone, and some more common bird species took up the aviary. I don't know where the h*ll they got it from, though (it's not exactly a professional zoo - doesn't report to ISIS, have a lot of animals in bad environments etc. - so I doubt they have that good connections).
Sadly, I did not ask at that time what the deal was with it. But it was surely an unique experience, even though the bird just lived in what resembled a parrot aviary.