Surely the most active and known Italian band at this time is To Kill (Rome).
There are a lot of names known in the rest of europe or even in other parts of the world thanks to their live activity :
Payback ( Rome )
Strength Approach ( Rome )
Affluente ( Ascoli )
Concrete Block ( Torino )
Straight Opposition ( Pescara )
Bull Brigade ( Torino )
Ingegno ( Perugia )
Face Your Enemy ( Caserta )
I think anyway that if you ask someone else the same question he/she will reply with different names and I'm sure that I haven't remembered some very good bands :)
Unfortunately hardcore right now is in a bad period. In my opinion there is a big loss of attitude. A lot of bands just care about the style, clothes, the appearance, the way to move on the stage. But there are some good bands who still try to send a message to people at shows.
Historically Italy has a big political background in punk/hc music. The previous generations were fighting everyday for their values, now it's different .
Some people, especially youngsters, don't know anything about politics, human and animal rights and they just think about the pair of new shoes to buy, just because they grew up with the playstation and tv.
Some others do like the past generations, they are still fighiting in squats, writing manifestos, having sit-ins, every kind of demonstration and supporting the diy culture and punk hc bands.
Talking about bands who have something to tell...some of them talk about respect, antiracism, antifascism, anticapitalism, critical attitude, straight edge, veganism and vegetarianism...just the same as the other meaningful hc punk bands in the world.
Some more links:
Values Intact RIP (Palermo)
To The Embers (Milan)
While You Wait
My Own Voice
Some historical old school bands: