Reply #3: I remember that..

[LibLabUK]

"Actually, one of the worst diasters involving the theft of radioactive materials occurred in Brazil, at Goiana, where a cancer treatment machine was stolen by illiterate thieves."

Not quite. It was an illiterate junk dealer, he took the canister of powdered Caesium-137 home from a site of an old hospital he was picking over. He opened it up at home and irradiated himself, his wife and kids and managed to spread the radioactive powder all over his neighbourhood (shantytown). It wasonly a local doctor (actually a veterinarian), who was reasonably on the ball, that realised what was going on when he was seeing so many people with the symptoms of radiation sickness.