A few weeks ago, one of our cats went missing for eight days. A hideous week, and so homemade 'Lost' flyers were stuck through letterboxes and posters put up around the local area. Thankfully, she reappeared as mysteriously as she disappeared (4am, and noisily, at the bottom of the bed), so all the posters were taken down.
Even as distracted as I was, I kept noticing the telltale signs of other signs and posters. Many may not have been lost posters, of course - home-printed posters advertising zumba are fairly common round here - but I did view the rusted staples and pins with an understanding empathy.