I didn't say it wasn't a "good" place. I said it was illegal. You know, just as occasionally some nut notices that it would be much faster to drive on the sidewalk, the street being so cluttered with cars.
And if idiots clutter up your bridge supports and public infrastructure with a lot of stick on electronic krep, it makes it a lot easier to hide a bomb.
How do you know this? Where I live it's legal to place advertizing on public property as long as it doesn't permantly deface the property. Thus you see clutters of signs by the side of the road, and even an occasional magnetic sign on metal poles and such, though those dont' seem to stay for long.