19 people were arrested in Italy on Monday on charges of forming mafia groups connected with the football business. Most detainees are top ultras — or hardcore fans — of Milanese football clubs FC Internazionale and AC Milan. The move “decimated” the leadership of fan groups backing two iconic Serie A clubs, local media reported. Prosecutors said at a news conference that possible charges include criminal association with the use of “mafia methods,” extortion, assault and other serious offences. According to the wide investigation, the criminal ring was linked to ‘Ndrangheta, the Italian mafia…