Hi,

  I have a friend to found a way to make money with 0-confirmations spending, I know is not ethical but it is really working and I wonder what are the legal risks?

  He found several sites, that can be used to make money.

  One is a bitcoin mixer, that works with 0-confirmations.

  Basically, this mixer works like this: you give it a bitcoin address where to return the mixed coins. Then the mixer provides you with an address where you send the bitcoin to be mixed. After the bitcoin receives the bitcoin to be mixed, it sends you bitcoin from a different addresses, basically different bitcoins, so that the bitcoins links are lost.
  The bitcoin mixer has some sort of buffer or reserve of bitcoins from where it sends you.

  The thing is that the mixer is not configured properly, and it sents you bitcoins from his reserve as soon as it sees 0-confirmation transaction from you to the address that it gave you to send bitcoin to be mixed. So it doesn't wait for your initial transaction to be confirmed 1 or more, it just sends you our the amount it sees coming, less fee, as it things it will get those bitcoins.

   The catch is this: if you send it any bitcoin amount with a very small fee, ex 1 satoshi per byte, the mixer sees the transaction, sends you bitcoin to your output address, but it never receives your initial bitcoin because the transaction doesn't confirm, and gets back to your wallet in about 3 days or so, after it gets dropped from the mem pool

   This is a great way to double bitcoin. Any amount can be send to mixer, the mixer sends back before it has confirmations of receiving, and then the initial transaction reverses because of small fee.

   It is not ethical but is proven. I am not sharing the link of the bitcoin mixer, because I do not do advertising of it, nor I want to promote illegal ways of doing money.

   I am just asking, due of nature of bitcoin, is very difficult to catch a person making bitcoin this way. But what are the legal risks if he gets caught?

   I am sure this glitch in configuration won't stay long. So I need to consider the legal risks fast before the thing gets properly configured

   My friend has sent it several times various amounts of bitcoins, and it always worked, getting bitcoin back twice.