My grandfather (born Philadelphia 1932) always told a story about how kids in his town would go to the train tracks in the winter and throw rocks at the engines. This would prompt the conductor to throw back pieces of coal from the engine to shoo them away. They would then pick up the coal and run away to use it to heat their homes. The conductors always knew what was going on, but it was the railway's coal, so they just always played along.

Anyway, always found that interesting.