I think I know which "neighbors" dumped this board in front of my garage door, but I can't be sure, so I left a prominently placed shaming note hoping they'd see it. Always satisfying!
UPDATE: Either there are old, termite-eaten wood rustlers in the neighborhood or my note worked. Just saw my (nice) neighbor, and she said her son laughed at the note in the morning. ("That's so Amy!" he said.) And then, when they came home later in the day, the board was gone.
Yay! Positive shaming!