I have a feeling whoever punched him is going to end up with more than a bloodied mouth.
As somebody said, either a brick or brass knuckles. This was more than just a “punch.”
I’m betting radical leftist. They hate Berlusconi, and Milan is one of their big hang-outs. Also, they’ve been very violent lately, even against more moderate leftists (the incidents in Berkeley where they were attacking the university president’s house, for example).