This is incorrect. If you have $1000 in bitcoin and send it to a tumbler in say 5 transactions of $200 each, and you specify that each of those transactions should send the output as 2 different transactions of $100 each, to different addresses, then there is no way to defintively link those addresses back up (unless the person sends all those coins back to the same address and even then it would take a lot of work to match them up again).<p>I think you think that someone sends $1000 btc to a new addres, then $500 btc to address 1, $500 to address 2, does this a few times and then sends all the coins to address 56, which then holds $1000. This would be possible to trace but would be time consuming to do.<p>The method I mention above would safely unlink any coins in the final addresses from the $1000 you started with.