I just want to clarify what I said in #1. Theft is an issue for travelers throughout Europe, and that's true on trains, also. Travelers have to be diligent about keeping an eye on their belongings, but I suppose you could say that when traveling anywhere in the world.
My response was predicated on the wild stories, many of them exaggerated or untrue, about gassings and other more dangerous crimes that are often told about certain train lines in this part of the world. I have traveled extensively on trains in this region, and I know many, many others who have, too. I've never heard a first-hand report of any of these wild stories...they're all third-person, friend-of-a-friend retelling, probably untrue but certainly exaggerated.
Be smart, use common sense, and you'll almost surely be fine. Get a sleeping compartment for the peace of mind, and to get a good night's sleep.
Dave

