I'm told a couple days ago (just before the heavy rains came through) acouple Burlington Northern employees were inspecting the right-of-way through downtown Tulsa, and found a couple caches of dozens of tennis balls, with about a one inch circle cut in them and filled with that quick-drying concrete, turning them into heavy, perfect-sized rocks for throwing.through windows, at people, at vehicles, etc.
Messing with train right of ways is a felony. These things clearly weren't meant to damage tracks or trains, but Homeland Security and local law enforcement was notified anyway.
Onward and upward,
airforce