Can trains be hacked?

Here's a presentation from last month's 28th annual Chaos Communications Congress (28c3) in Germany asking, "Can trains be hacked?". Unfortunately for me, while many or most presentations at the conference are presented in English, this one is in German. I only ever took two years of German language classes, so this is well outside my ability to understand. It does include some nifty videos of training centers for old mechanical interlocking stations and more modern electronic ones.