I've been to Naples in the south, and it's one of the dodgiest places ever. Get off at the train station in Naples and you really have to watch your shit, lest it be snatched from you. I was ok, but unfortunately, the asian tourists are often seen as 'easy targets' and are set upon by the local scumbags. Once you keep going south however, into Sorrento, Positano and Amalfi, it's probably more beautiful than the places in the north of italy imo, so I don't understand why the northerners think they're so much better.