Coinbase is a bitcoin wallet and exchange company headquartered in San Francisco California, founded by Brian Armstrong and Fred Ehrsam. It operates exchanges between bitcoin and fiat currencies in 32 countries, and bitcoin transactions and storage in 190 countries worldwide.
Coinbase has three core products: an exchange for trading bitcoin and fiat currency, a wallet for bitcoin storage and transactions, and an API for developers and merchants to build applications and accept bitcoin payments.
http://www.techworm.net/2015/12/hacker-ddos-coinbase-website-down.html
