Welcome to this module on the challenges to implementing blockchain. It's an important one because there are still many blockchain naysayers. Like every revolutionary technology, the blockchain has it's upside and it's downside. In this module, we discuss 10 different implementation challenges. Some say blockchain is too easy for criminals to use. Other say blockchain is just too hard for everyone else to use, compared to say email or social media. Still others say it burns too much energy. Some call it a job killer, a surveillance system for the state, a platform for big incumbents to get bigger. Still others are worried about governments banning it in China, Russia, and elsewhere. We need to overcome all these, as we move into the second era of the internet. Just beyond all the legitimate concerns of naysayers and the resistance of incumbents and Luddites are reasonable and compelling arguments for moving forward. We'll walk you through them. Remember, we need more debate, more engagement in this blockchain revolution, not less. Thoughtful and respectful debate is helpful. Attacking each other on Twitter is not. By the end of this module, you'll be able to describe each of the challenges. And for each challenge, you'll be able to describe one or more possible solutions. If you've heard any blockchain bashing, please share it on the discussion forum. We need to get all the arguments, pro and con on the table. For a preview of these implementation challenges, see chapter 10 of blockchain revolution. On behalf of my co-author Don Tapscott and our academic partner INSEAD, thank you for joining us.