Check out these wallets

This first wallet is from the Chicago Transit Authority's (CTA) Gift Shop:

The Mighty Wallet is printed with the licensed graphics of the CTA and is not only functional for quick transfer info on the go but it also adds a level of stealth that safeguards your valuables from theft. Mighty Wallets have actually evaded theft in real life situations through their uncommon stealthy design.

Made from Tyvek (think express mail envelopes), the Mighty Wallet resists tearing because of thousands of interlocking plastic fibers spun in random patterns giving the wallet incredible strength.

This might be very cool. Such a wallet can foil theft attempts, especially if a potential pickpocket thinks that this is merely a CTA Map.

Also check out this second wallet:

A dot-matrix wallet from ThinkGeek. The description doesn't mention foiling thieves, but it does mention that it's made of a similar material to the CTA Mighty Wallet. The fact that it's a dot-matrix wallet should ring a bell to old-time computer geeks.

Some of the other wallets you might find at ThinkGeek may have some added features that may foil criminals. Although the hazard isn't necessarily to think of actual pickpockets or theft as opposed to a theft of a different type.