Crowded or not, it can happen. And it's certainly not impossible. I've seen the same kind of thing happen -- albeit in Rome -- on a rather empty shopping street at a time when there was no crowding, and on some rather empty steps going up from a rather empty plaza that had no crowds at the time it happened.

Pickpockets don't necessarily need a big crowded area in which to successfully take goods from a mark. They just need a mark who is distracted, a mark whose placement of "valuables" is accessible to the thief without its attempted and actual removal being readily noticed by the mark and/or those physically very proximate to the mark. As I've said before, some of the pickpockets in this area are very skilled at their work. And to paraphrase a victim of one such theft -- or rather the spouse of the victim -- who had to call and cancel a couple of credit cards because of one of those thefts (and had to get a replacement of various other cards/docs): the thief was so "good", the thief really earned "his" keep. And yes, it was a stolen pocketbook from inside a small purse inside a locked backpack. Not an urban legend, The real deal.

But what's wrong with the water in Venice? I really don't get the issue with the water. I have brushed my teeth there and drunk the regular water from taps/fountains there and never had an issue. Is there a "Venice belly" equivalent to "Delhi belly"?