In terms of putting Italians away I go with the theory that Flemmi gave up most of the info on the North End guys. I'm sure Whitey wasn't really plugged in with them to know more than what they wanted him to know whereas Flemmi was in tight with those guys. If I recall correctly he turned down the button several times. They tolerated Whitey because of his LE sources, and eventually because he inherited Howie Winters debt.

I absolutely believe, however, that Whitey snitched on anyone in Southie who he perceived as a threat and didn't want to just kill for whatever reason. Pretty sure it was Pat Nee who Whitey sent on an armored car robbery and then tipped the Feds about it. I think he even sent Nee on the robbery with an empty gun.

As for Tameleo, Greco, Limone & Salvati, that was all Joe Barboza, who had personal grudges with those guys for various reasons.