http://www.dig4coins.com/news/latest-news/the-fears-of-antiquity-revealed-by-ancient-coinage
About 1,650 years ago the Roman Empire was flooded with treason, profanity and presumably defacing of the coinage. People who started all this cursed Valens and hammered a coin with the Roman emperor's image into lead, afterwards folding the lead over Valens' face.