Bitcoin

Digital currency Bitcoin has grown sensationally, with 11 million Bitcoins worth nearly $2 billion in circulation. It's the ultimate Internet-age currency: Bitcoin circulates only online, trades anonymously and isn't regulated by any government.

Whenever there's a big economic crisis, investors usually flock to the safety of gold or U.S. government bonds. But when things got crazy in the last couple weeks in Cyprus, it was something called Bitcoin that surged in value.

Amid the banking crisis in Cyprus, an online-only currency called Bitcoin is getting new attention. How does the currency work and who regulates it?

This week, the retailing giant said it will soon offer its own currency, called the Amazon Coin.

There's a website you can visit to buy all your drugs - heroin, LSD - you name it. It's called Silk Road, and you have to be pretty tech savvy to...