According to the doorman, the Roman panaroma was being slowly worn away by the continuous gaze of tourists, and if no action were taken, it would soon be entirely used up. ... In a second footnote he emphasized, as proof of his thesis, how the view visibly worsened in the spring and summer, coinciding with the greater crowds of tourists, while in the winter, when tourists were scant, one noticed no change for the worse; on the contrary, it seemed the panorama slowly regained its traditional limpidity.
-- Luigi Malerba, "Consuming the View" (tr. Lesley Riva from the Italian)