I’m only surprised they were dumb enough to get so easily caught. I know people pilfer stuff from there all the time, but it’s usually a small chunk of concrete from a crumbling foundation or a rock to place on a grave back home.
My primary hobby is researching, collecting and writing about the US military in WW2. I have a lot of impresive items in my collection but next to no German stuff. Having been to the terrible places that are associated with the Third Reich, I wouldn't want anything like that. It’d never occur to me to want any “souvenir” from that horrible place but anyone could see that a spike from that line is truly iconic.

I remember seeing a photo in the local newspaper a while back, as part of an article on the camp. It was taken by placing a camera between the rails, and looking towards the gate house. When I saw the picture, I distinctly remember thinking that as far as Railroadiana goes, I don't think you could get anything else that even comes to close to the creepiness of a section of THOSE rails or a spike etc.