It is great that somebody (the FBI?) has made these maps of the various Sicilian, Calabrian and Neapolitan groups in the USA, but what exactly do these groups do?

Other than the recent bust in February of the drug conspiracy involving Raffaele Valente (ndrangheta) and Franco Lupoi (associate of Frank Cali), you never hear about the ndrangheta in the USA (as opposed to Canada), and most Sicilian groups have presumably been absorbed into the American mafia. Or do they operate independently?