As with any locale you are unfamiliar with, it pays to be alert while traveling within large crowds, especially during the high season. Pickpockets can quickly pick you clean of your money or passport, quickly turning a dream vacation into a nightmare. Make use of your hotel's safe to protect items such as any jewelry you might have brought with you (which, in reality, is best left at home), extra monies, credit cards, and passports. Keep your eyes and a hand on bags at all times, and do not leave your items unattended. If your hotel does not have a safe, you should plan on keeping your passport with you; your safest option is to utilize a money belt to hold both your passport and any cash or credit cards; the belt is easily tucked discreetly beneath your clothing.

In addition, when traveling abroad, it is often easiest to travel with traveler checques (which can be purchased at home in Euro denominations from most banks), which are easier to replace than cash or credit cards if stolen. Keep a copy of the front page from your passport, any tickets, traveler checque serial numbers, and any other important information in a location separate from the originals. You may also consider leaving a copy of these pages with someone back at home, whom you can contact if necessary if you get into trouble abroad. These copies will come in handy if you are a victim of theft.  

The latest travel warnings for Italy can be found on the US Department of State Consular Information sheet for Italy.