3 ms·

I dont think it has?

• IncRnd 8y ago
  You don't think what has? There have been double spend attacks against BTC.
  • Jommi 8y ago
    source?
    • zeven7 8y ago
      Not exactly a double spend, but billions BTC being printed out of thin air: https://bitcointalk.org/index.php?topic=822.0 https://bitcointalk.org/index.php?topic=822.0
      • celticninja 8y ago
        It has happened before but that was in 2010 when the codebase was < 2 years old.
        • IncRnd 8y ago
          It's happened quite a few times after that. Consider the merchants who have been known to use fewer than the standard # of confirmations and what it takes to reverse or reuse those charges. For example, here is a blog post on one way to do this: https://blog.acolyer.org/2015/10/01/misbehavior-in-bitcoin-a-study-of-double-spending-and-accountability/ https://blog.acolyer.org/2015/10/01/misbehavior-in-bitcoin-a.... If you want to search you will find that there are scripts to automate this type of action by constructing bitcoin transactions. Also, consider ghash.io or the odd OKPAY double spends.