If you know where to look, you'll spot these 22" x 28" posters stapled to telephone and light poles in many of the lower income neighborhoods of Los Angeles. Finding and retrieving them (some are way up off the ground) is more fun then the actual painting.
Like the American Indian, I take only what I need after their date has expired, or when there are lots of the same ones posted in one area. I'm all about conserving and protecting shitty outdoor advertising for future generations.