My partner and I took the overnight Cruz del Sur bus from Cusco to Puno. Our backpack was under our own seats. While we slept, someone opened it and took about S/1000 in cash out of the wallet inside. What's almost unbelievable is that everything else in the backpack was exactly as we had packed it. Only the money was gone. They didn't touch our bank cards, IDs or anything else with our names on it. These were clearly professionals: cash can't be traced back to you. Even if you notice the theft while the bus is still moving, there's no way to prove the money in someone's pocket was yours. We only noticed the next morning, by which time we were already on a taxi. Lessons: On overnight buses, keep cash on your body. Never leave it in a bag under your seat or in the overhead rack, even if it's right next to you. Split your cash across several places. A premium bus company doesn't mean your stuff is safe while you sleep. Not a disaster (about $265), but a very avoidable one. Stay safe out there.