From their site: "This challenge started in February 2015, and will run until the above address no longer contains the 10 bitcoins it started with, or until we

From their site: "This challenge started in February 2015, and will run until the above address no longer contains the 10 bitcoins it started with, or until we lose interest. In 2018 we will likely reuse most bitcoins for other projects." So I'm not sure what happened frankly.