I'm guessing that it's not that anybody sees anything wrong with it, but more so to let people know to leave them alone which I hope people do. As it is, my husband and I had to get after a group of little girls last night who were throwing large rocks at the ducks on the lake and coming quite close to hitting them. What is wrong with people that they'd let their children (I believe their parents were nearby) try to hurt animals??? This isn't the first time we've seen it happen either, unfortunately. I'm just happy that us speaking up gave the ducks a chance to get away. The swallows wouldn't stand a chance if someone chose to disturb them, but at least anyone who does disturb them can be held responsible.