It is amazing how often acid treated coins appear on eBay and forums. Mostly labeled as struck on foreign or thin planchets. Once you learn to recognize the type, they can be spotted a mile away. They all have that fuzzy detail look, are usually much thinner than a normal coin with surfaces that are somewhat pitted. If you search eBay with the word thin, several examples will always show up. I wish I could round them all up and bury them. I hate to think how much money people lost on these but we all have had some hard lessons, I guess some harder than others.