Bitcoin is the virtual currency par excellence. Barely a day goes by without it being in the news, either due to wild swings in value, or the multiple reactions it provokes. There are many who argue it should be regulated, and some even suggest banning it, such as the Nobel Prize winning economists, Joseph Stiglitz and Jean Tirole. But what are bitcoins? Who issues them? How do you buy them? What do they mean? What benefits do they give? Do they entail risk? Is regulation needed?