There will be a demonstration today (una manifestazione) against several attempts by Berlusconi that try to make him immune to Italian law. It will be held in Piazza del Popolo, which will likely be packed, if it's anything like the other anti-Berlusconi demonstrations have been.
Basically, the Prime Minister is in a bunch of trouble with the law for corrupt business practices of his and now he is trying to change Italian law so that he cannot be punished while he is Prime Minister. This rally will be a united rejection of this.
I personally recommend that, even if you are not so interested or informed in Italian politics, to come out today. These rallies are usually really interesting, if not entertaining. I guarantee that if you go you will not forget it. Hope to see you there!
"La legge è uguale per tutti" -- The law is the same for everyone