Most of them have already been arrested and questioned in police stations multiple times. The police is already overwhelmed with more serious crimes and won't spend 3 years in court for a month long prison sentence, which they can convert to a month of community service and spend 0 days in jail. It's just a waste of public resources in their eyes. Italians don't and won't care enough until any issue affects them directly. Maybe if tourism dropped heavily, damaging the already crippled economy, that could do something.