One should be very careful with coinjoin and mixing too. For example, it's not recommended to coinjoin through Wasabi. Also, one has to keep in mind that one might get in trouble if receives money from a mixer with a bullshit AML score.
Wasabi is the best for coinjoining because it provides complete privacy. The non-recommended coinjoin protocol is Whirlpool, because it links your transactions together by revealing common input ownership and creating traceable change:
Post the tx ID of any Whirlpool transaction and I will show you the tx0 transaction that was created by each of the new entrants.
Ok, here's one: https://mempool.space/tx/ed3131b544fbf00a71709942e483b55e629312ecb181e6e819409f419ee0d226Where exactly is the privacy loss for new entrants, splitting a single UTXO in to multiple UTXOs to join the pool?
Okay, here's all the payments that can be tracked from the two new participants of the Whirlpool coinjoin transaction:
Entrant 1: bc1q03c0443ausjjdxl2h6ud5m8c0dux0zyg3dqdj7 created 0.00170417 BTC in unmixed change sent to bc1q3fduld0l3r8nclyt5p3r7ak675tekurstn55tl. Since this UTXO is not private, the sats were marked as unspendable and have not been recovered by the wallet owner
Entrant 2: bc1qzc8zku26ej337huw5dlt390cy2r9kgnq7dhtys created 0.00191247 BTC in unmixed change sent to bc1qjlltxr443uy236wl4xhpxlr6dgsu0zltlv3m44. This UTXO was used in a second tx0 transaction, creating a huge trail of transactions that could be traced to each other
The 2nd tx0 transaction created 0.00076348 BTC unmixed change which was sent to bc1qehd7gy8rza9mnzm9wnfjhgw82rp47wmqt7vpgy
Since this unmixed change is below the .001 pool minimum, it was consolidated in a 3rd tx0 with 3 other addresses owned by the same wallet:
31x8GPqrhzdaxiBJa9N5UisuoxbX1rAnHa
16Gw5WKjbxZmg1zhZQs19Sf61fbV2xGujx
3LZtsJfUjiV5EZkkG1fwGEpTe2QEa7CNeY
The 3rd tx0 transaction created .00200317 in unmixed change which was sent to bc1q2p7gdtyahct8rdjs2khwf0sffl64qe896ya2y5
This was spent in a 0.00190000 payment to 3B8cRYc3W5jHeS3pkepwDePUmePBoEwyp1 (a reused address)
That payment left .00008553 in change that was tracked to 3Dh7R7xoKMVfLCcAtVDyhJ66se82twyZSn and consolidated with two other inputs in a 4th tx0 transaction:
bc1qeuh6sds8exm54yscrupdk03jxphw8qwzdtxgde
3ByChGBFshzGUE5oip8YYVEZDaCP2bcBmZ
This 4th tx0 created .00533406 in unmixed change which was sent to bc1qzh699s75smwukg9jcanwnlkmkn38r79ataagd9 which was consolidated with 3 more addresses into a 5th tx0:
3F2qiWQJKQjF7XFjEo8FUYP3AU5AC6RqX8
3HAYYVKUpYbr2ARMdZJr9yVu8xi8UcxtPz
3GQtwwRK31wwCc22q6WS5sCgixUHsG5KaT
The 5th tx0 created 0.00058494 BTC in unmixed change that was sent to bc1qvh2zjcwwkj9y70xulla2semvlav3lty0p3l3w3
This was spent in a .00047290 payment to bc1qvzg8jq6wqtr5navn4e3ps4qrkk9r6n4h98gjck
That payment left .00008411 in change that was tracked to bc1qg6j0f0wfhpktt2l8uzdn48ct3um2xyur40eyzd and consolidated with another input into a 6th tx0 transaction:
31iZLXWfoywhuMZTPGxTkpzphzh2NXshpP
The 6th tx0 created .00753775 in unmixed change that was tracked to bc1qgfll2apc27yct6h2c8r8wq4kqhxjsfrudhhn5q
This was spent in a .00737000 payment to bc1q5emzer2t0sq5dez0zsrqgh6scvwn0n24xsladp (a reused address)
This payment left 0.00010896 BTC in change which has not been spent yet, but the payment only took place 11 days ago, so I assume it will eventually be spent, allowing the Whirlpool user to be tracked even further.
