A pile of speed camera guts, 10 meters of 900-pair phone line, a grounding grid from a substation, and some coils from an orphanage's air conditioner, probably.
I remember the school buses in one high school I went to running on propane. It's not as clean as electric, but it's cleaner than diesel... and at the time, an electric school bus would have been expensive, if not outright science fiction.
sugar into a concrete mixer and prevent construction and such
I used to work for a concrete precasting plant. A single 20oz bottle of coke will ruin ten cubic yards of concrete easily.
But it's even easier than that. You can spray forms/reinforcement with soda before the concrete is even poured, and it will ruin the pour because the concrete won't bond to the reinforcement.
I love the bantam egg on top.