Let's not be hysterical. I'm sure this was a localized problem. I live in Roma and haven't seen any blue balls of the kind in the supermarkets I can assure you. In any case each consumer can see for himself if the product is tainted or not.
A few years back, however, there was another mozarella scandal on a much more serious level. It took place in the Neopolitan zone, where the best mozarella di bufola is made, because the Camora (Naple's mafia) was dumping toxic waste in areas where the bufola (buffalo cattle) grazed which caused their milk to be venomous. There was a public outcry which led the national government to step in and clean the zone which has seemingly resoved the problem.