Author Roberto Saviano bemoaned restrictions on freedom of expression in his home country of Italy during an appearance at the Frankfurt Book Fair on Saturday. “For me, being here is like revenge (‘vendetta’),” said Saviano, known for his best-selling mafia exposé “Gomorrah,” which was widely translated and adapted into a film. But despite his international reputation, Saviano was not included in Italy’s official delegation for the Frankfurt Book Fair, the world’s largest book-industry gathering. Italy is included as the Guest of Honour for this year’s fair. Saviano instead came to Frankfurt a…