In an attempt to save the situation, the prosecution called in an IRS agent to testify that, using an accounting method called LIFO (“last in, first out”), one could argue Lin’s stolen funds did indeed go to Tornado Cash. While LIFO makes sense in some circumstances, such as its common application by businesses accounting for their inventory, it’s a poor choice in this situation. Essentially, the agent testified that, if you assume that the last funds into a wallet are the also the first funds to be withdrawn, it can be established that the scammer’s deposit into the chainswap service went to Tornado Cash.
Let’s use an overly simplistic example to illustrate the problem here. Let’s say you have $1,000 you want to move from one of your bank accounts to another bank account. For whatever reason, you decide the best way to do this is to walk to the corner shop and have them make a money transfer for you. The guy at the counter takes down your account information, puts it on a pile next to him, and you go about your day. Behind you in line, some other person is planning to send $1,000 to an illegal arms dealer. She gives that account information to the guy at the counter, and on the stack it goes. Later that day, the clerk processes the transfers, sending $1,000 to your bank account, and $1,000 to the illicit arms dealer. Later, an ATF agent shows up at your doorstep accusing you of buying illegal guns, because the transaction from the person behind you was the last one in to th