Bitcoin is the virtual currency that's all the craze right now. It even has some powerful allies, like's C.E.O. Patrick Byrne whose popular shopping site accepts Bitcoin and promotes reward programs to push the use of the currency.

But as Daniel Altman wrote for Big Think, there's still so much we don't know about Bitcoin, indicating potential problems. 

Here are 10 things we do know, including some facts about Bitcoin that may surprise you: