Judging from the literature on the subject, chiefly Maurer, Icardi and Campion (a less scholarly source, perhaps, but a career whiz cop), I would say that there is no safe pocket. Wherever you put it, there’s a pickpocket who can get to it. But most of them are relatively low-skilled and looking for easy scores. The problem is that it takes surprisingly little skill most of the time. Your best bet is not to be an easy enough mark.
In a strange city where I was obviously going to stand out as not able to stay long enough to make trouble with local law enforcement, I would not keep valuables in pants pockets at all. You might think your pratt pocket is too tight and you’d notice someone touching you in the ass, but you’d be wrong. It may be that the breech pockets on tight jeans are too difficult to get into, but certainly the breech pockets on trousers with linings that can be pulled inside-out are completely insecure however tight your pants are. Don’t use a wallet on a chain unless you’d like to find it dangling empty at your side.
Side pockets on your jacket are great places to store money you don’t want. Inside pockets are harder to get to, and may force more drastic measures to get to, such as a “throw” with a newspaper or a “keister plant” from an attractive female. Better still, pockets under a sweater or other articles of clothing. The lanyards that hold the wallet under your shirt but around your neck sound pretty good – not impossible to get, but risky and tricky even for serious cannons, if any are left out there.
If the pattern persists as it had in the previous centuries, it’s an unstoppable problem because of the fix. You can put the fix in to “grift right” (i.e., the police staying out of your way). You can put in the fix after the fact, paying the officer who arrests you, or anybody else up the whole bureaucratic and legal chain that leads to conviction. Or, quite often you can pay a “fixer” to put the fix in for you. As long as your take exceeds the fall money you’re doling out, you’re operating in the black. By picking on tourists, you make it easier for everyone to simply stall the process until the foreigner has to go away, and can’t conveniently show up to testify in a trial or pressure local politicians.
Once in a while, they will make a show of cracking down, which generally means that some other city will get a huge upsurge in pickpocket activity for a while.
It is believed that pickpockets hang around “beware of pickpocket” signs because when people see it they instinctively check their belongings. This gives pickpockets instant data as to where your valuables are, saving them the risk-enhancing step of “fanning” the mark to locate valuables.