+1 to what Mike said.
For people with half a brain this entire thing is not even a problem. The really important things (passport, ticket, 1 credit card) go in a pouch that is stuck to the inside of your waistband. They would have to strip you bare to get it out.
Everything else you just take so little and so non-valuable that you aren't a target.
Obviously, if you trapse around with an Hermes Kelly bag, you're a prime target. Same thing goes for promenading with a huge DSLR and a fat white lens attached to it.
The latter means you are a rich enthusiast or prof. photographer. In both cases your equipment should be insured against theft and you will be doubly aware of your surroundings.
If you (general you) walk through Rome or Barcelona with a wallet in your backpocket you are so dumb, you deserve to be the victim of a pickpocket to teach you a lesson. Money well spent.
