It's only reasonable to use privacy-friendly features to make transactions in Bitcoin. Just like how you don't want to show the contents of your bank account to the people you send money to with regular banking, you wouldn't want the same when using Bitcoin, and this is what coin tumblers/mixers/aggregators or whatever you want to call it attempt to solve. My question is, when it comes to blacklisted coins, doesn't CoinJoin have the same problem as regular online mixers? Since you never know where the coins come from, you may end up blacklisted coins and when you go and make a transaction, you may own blacklisted coins that show up at the end of some service that uses whatever filters they use to detect so called blacklisted coins. So ideally you would want to end up with fresh coins, but I wonder how since the only guaranteed fresh coins are recently mined coins.