Several news outlets are reporting today that Venice has definitively banned cruise ships from sailing down the famed Giudecca canal, through the heart of the city, after a number of recent incidents in which large ships have either collided or nearly collided with smaller craft. This follows many years of concern and complaints about the damage caused by such ships and the overcrowding they lead to in Venice itself.   So far, most of the articles I've seen have been very short on deta