Privacy coins dont exist. They are just a cryptocurrencies. Money have to be fungible. And for a cryptocurrency to be fungible it needs opaque ledger. It is silly to call coins private, if they are just what money should be.
Privacy coins do exists just look out news on how countries like Japan and Korea are planning to remove complete the listings of this "anonimity/privacy coins" that is currently available on their exchanges. Some popular anonimity coins like Monero, Zcash, and Dash are more anonymous compared to Bitcoin thus making a shift from criminals doing illicit activities from the coins I have mentioned, even the authorities have said that they know that these cryptocurrencies now are being used to criminal activities.