In some European countries there can be pick pockets. As you are looking up at an old building, someone is in your purse robbing you blind. Or someone cuts the strap of your purse off and runs around with it.
Money belts or Security Purses are the key. I used a money belt in Italy and never had a problem. However, I did hear passengers talking about being pick pocketed. Security Purses have a slashproof front panel, steel wire-reinforced adjustable shoulder strap with interior anchor, and concealed safety hook on the front flap.
My mom has this one made by Magellan. Magellan makes lots of security stuff including backpacks and laptop cases all with the slashproof front panel. We got are stuff at REI, but you can order direct.