I suspect the perpetrator is either of two morons from alt.home.lawn.garden.
One is a professional lawn chemical thug who doesn't like that I pointed out
how the products he sells are unsafe, and cannot be proven otherwise. The
other is a homeowner - an enormous lard ass like the kind Dick Gregory used
to haul onto an airplane with a forklift and take to his weight loss clinic
in the Bahamas. He's simply to huge to stand in front of the library shelves
and learn how to take care of his lawn without poisoning it. So, he takes
out his frustrations this way.