A racing spectator's photo of a gravel safety strip covered in crushed cans is drawing anger online after the fan criticized what they said had become an accepted littering habit at a major motorsports event. What happened? The spectator posted the image on the r/MildlyInfuriating subreddit after taking it beneath the outfield bleachers at the Indianapolis 500. In the shot, the gravel area beside the track appears to be packed with discarded alu…