The correct answer is the acting capo of the Barese crew, Albert Barese.

The Aprile crew and the Barese crew were feuding with each other over garbage contracts. There was no blatant violence between the two crews, but each crew was looking to hamper the other's business by destroying the other's garbage trucks and dumpsters.

This was put to a stop by Tony.

You can see all this in Episode 2 of Season 3.