Not really a valid argument, Stan, except from a devil's advocate point of view. I live just outside Chicago. I visit Vegas. In both those areas, I know where the bad areas are and stay the hell away, regardless of how much $$$ I'm carrying on my person. Where I'll be--Paris, Lucerne, Milan, Florence, Naples--I really have no idea where I shouldn't be. And besides, this 'petty theft' seems to take place more often than not where people congregate--trains, subways, tourist attractions--not 'bad' areas, per se.
So it's inevitable that in those European cities I will be in areas where that kind of crime could take place. I guess my final answer is to wear a neck pouch with everything, pay cash whenever possible (to minimize credit card scamming), utilize the debit card only at bank ATM's during working hours (so I can get the card back if the machine eats it), and, finally, to enjoy but be aware of surroundings. I've been in enough bad neighborhoods to be able to sense that if it feels nasty, it usually is.