Also the printer that would jam when printing one file: http://nedbatchelder.com/blog/200811/print_this_file_your_pr...
Just because a bug seems impossible doesn't mean it is.
This comment reminds me of the magic switch (story [0], light HN discussion [1]).
[0]: http://catb.org/jargon/html/magic-story.html [1]: https://news.ycombinator.com/item?id=181045