The Art Media Agency reports that Italian authorities have broken up an art counterfeiting gang. They were making replicas of Greek and Etruscan antiquities and selling them to collectors at "real" prices.
The authenticity "credentials" were being altered by a hospital employee with access to x-ray machines to falsify dating results. Hundreds of thousands of Euros were involved, along with victims who should have known better. They say, in fact, that it was one collector's suspicions about the surge of previously undiscovered work being offered that triggered an investigation.
The moral is to question everything. And remember your best defense and assurance of authenticity is a reputable dealer who will stand behind what you buy from him.