The ultimate deterrent, the "Brief Safe" is a pair of underwear with a 4" x 10" compartment for hiding valuables. It makes use of what it calls "special markings" on the "lower rear" to stave off would-be thieves. It comes in one color: "white (and brown)." This is disgusting!
Pick up a pair for $11 at Shomer-tec a military and law enforcement equipment provider. Shippings adds a heft $13.
Haven't touched your sensibilities yet? They also have Doo Drops, which "look and smell like real diarrhea" and were supposedly manufactured for "the CIA and other federal agencies."