You may have heard of BitCoin, the virtual currency that was introduced in 2009 and was used, at first, for transactions on some small website. Then they became popular on Zynga and Overstock.com, and now they’re being accepted at brick-and-mortar outlets, including two casinos in Las Vegas.

But what are BitCoins? How do you buy/sell them? Are they really legal? On my America Weekend show, I asked Jerry Brito, senior research fellow at the Mercatus Center at George Mason University and director of its Technology Policy Program. Listen to our conversation here.